GJFT  OF 


ENTOMOLOGY 
LIBRARY 


je  Eural  Science  Scries 

EDITED  BY  L.  H.  BAILEY 


THE  SPRAYING  OF  PLANTS 


A.   MILLARDET, 

PROFESSOR  IN  THE  ACADEMY  OF  SCIENCES,  BORDEAUX,  FRANCE. 

(See  page  26.) 


THE 


SPRAYING  OF  PLANTS 


A  SUCCINCT  ACCOUNT  OF  THE   HISTORY,  PRINCIPLES 
AND    PRACTICE    OF   THE   APPLICATION    OF 
LIQUIDS  AND  POWDERS  TO  PLANTS 
FOR  THE    PURPOSE    OF  DE- 
STROYING   INSECTS 
AND   FUNGI 


BY 

E.   G.   LODEMAN 

INSTRUCTOR  IN  HORTICULTURE  IN  THE  CORNELL  UNIVERSITY 


WITH  A  PREFACE  BY 

B.  T.  GALLOWAY 

CHIEF  OF  THE  DIVISION^OF  VEGETABLE  PATHOLOGY,  UNITED  STAI 
DEPARTMEMT  OF  AGRICULTURE 


gorfc 
THE   MACMILLAN   COMPANY 

LONDON :  MACMILLAN  &  CO.,  LTD. 
1909 

All  right*  reserved 

C—  JAUll 


GIFT 


COPYRIGHT,  1896, 
BY  MACMILLAN  AND  CO. 


Set  up  and  electrotyped   January,    1896.      Reprinted   September, 
1897;  August,  1899  ;   February,  1902;   September,  1903;  January,  1906; 
February,  December,  1908  ;  June,  1909. 


***   THK8I8   PRESENTED   TO    THE    CORNELL    UNIVERSITY    FOR   THE   DEGREE 

OF  MASTER  OF  SCIENCE. 


Norton olr 

J.  S.  Gushing  &  Co.  -  Berwick  &  Smith 
Norwood  Mas*.  U.S.A. 


K/.  flu  J,r 

TO 


SEINER    MUTTER 
IN   INNIGSTER   LIEBE   ZUGEEIGNET 

DER  VERFASSER 


445104 


PREFACE. 

IN  looking  back  over  the  past  ten  or  twelve  years,  it  is  dif- 
ficult to  realize  the  rapid  advance  made  in  combating  the 
insects  and  fungi  which  attack  our  cultivated  plants.  It  is  not 
going  too  far  to  say  that  the  discoveries  made  within  this 
period  have  worked  almost  a  revolution  in  certain  lines  of 
agriculture.  So  phenomenal  has  been  the  progress  in  this 
direction  that  we  are  sometimes  led  to  think  that  we  have  gone 
forward  too  fast,  for  in  our  intense  desire  to  make  the  work 
thoroughly  practical  we  have  in  many  cases  merely  skimmed 
the  surface,  overlooking  some  of  the  most  important  funda- 
mental questions  involved.  However  this  may  be,  the  fact 
remains  that  America  to-day  stands  well  to  the  front  in  the 
discovery  and  application  of  practical  methods  of  dealing  with 
the  numerous  insect  and  fungous  enemies  of  cultivated  plants. 
The  advance  in  this  department  has  been  so  rapid  that  it  has 
hardly  been  possible  for  investigators  to  keep  track  of  all  that 
has  been  written  on  the  subject,  nor  has  it,  under  the  circum- 
stances, been  an  easy  matter  to  pause  and  consider  what  is  to 
be  the  final  outcome  of  work  of  this  kind.  This  seems  to  be  a 
fitting  time,  therefore,  to  take  a  broad  survey  of  the  subject  in 
order  that  we  may  see  where  we  stand.  Mr.  Lodeman  has 
done  this  in  the  present  volume,  in  which  is  given  a  clear,  con- 
cise statement  of  the  existing  condition  of  our  knowledge  on 

ix 


x  Preface. 

the  spraying  of  plants  and  the  fundamental  principles  under- 
lying this  operation. 

As  to  the  future,  it  can  only  be  said  that  the  prospect  for 
broadening  the  work  so  well  begun  is  exceedingly  promising. 
As  yet  it  cannot  be  stated  that  we  have  a  well-defined  science 
of  plant  pathology,  but  gradually  the  investigations  and  thought 
in  this  direction  are  being  crystallized.  It  is  now  realized  that 
to  truly  understand  and  appreciate  pathological  phenomena  we 
must  be  familiar  with  physiology,  the  normal  life  processes  of 
plants.  After  all,  the  highest  aim  of  the  investigator  in  this 
field  of  research  is  not  to  deal  only  with  effects  as  he  finds 
them,  but  to  study  causes,  as  it  is  only  by  this  means  that 
the  true  nature  of  many  of  the  phenomena  involved  can  be 
obtained.  Following  this  line,  we  shall  in  the  future  look  for 
a  science  capable  of  elucidating  the  problems  which  form  the 
very  basis  of  agricultural  and  horticultural  pursuits. 

B.  T.  GALLOWAY. 
WASHINGTON,  D.C. 


CONTENTS. 

PART  I. 
THE  HISTORY  AND  PRINCIPLES  OF  SPRAYING. 

CHAPTER  I. 
EARLY  HISTORY  OF  LIQUID  APPLICATIONS. 

First  Applications  to  Plants  —  Present  Distribution  of  Insect  and 
Fungous  Parasites  —  Oceans  as  Barriers  —  Protective  Applica- 
tions the  Most  Effective  Measures  —  Spraying  Defined  —  Early 
Recommendations  —  Vinegar  —  Rue  —  Urine  —  Dung  —  De- 
struction of  Plant  Lice  —  Tobacco,  Water,  Powder  —  Soap  — 
Soot  —  Sage  —  Hyssop  —  Wormwood  —  Lime  —  Petroleum 

—  Turpentine  —  Tansy  —  Leek  —  Hellebore  —  Oils  —  Sul- 
phur —  Paints  —  Washes  —  Forsyth's  Composition  —  Ashes  — 
Sand  —  Plaster  —  Burnt  Bones  —  Decoction  of  Walnut  Leaves 

—  Train-oil  —  Whale-oil  —  Flax  Rubbish  —  Sea-weed  —  Sea- 
shells —  Sea-sand  —  Mortar  Rubbish  —  Clay  —  Tanner's  Bark  — 
Leather  Scraps  —  Salt  — .Corrosive   Sublimate  —  Alcohol  — 
Potato  Water  —  Decoctions  of  Elder  —  Bitter  Herbs  —  Pepper 
_  Lye  —  Pot  and  Pearl  Ashes  —  Tar—  Hot  Water  —  Soft  Soap 

—  Farmyard    Drainage  —  Brimstone  —  Burdock    Leaves  — 
White  Hellebore  —  Nitre  —  Whale-oil  Soap  —  Nux  Vomica  — ' 
Scotch  Snuff  —  Cayenne  Pepper  —  Aconite  —  Pigeon  Dung  — 
Eau  Grison  —  Quassia  Chips  —  Copper    Sulphate  —  Various 
Formulas  containing  these   Ingredients  —  Applications  recom- 
mended against  Canker  —  Cantharides  —  Plant    Lice  —  Me- 
chanical Injuries  —  Canker-worms  —  Red  Spider  —  Insects  on 

xi 


xii  Contents. 

Melons  —  Scale  Insects  —  Apple-tree  Borer  —  Slugs  —  Cater- 
pillars —  Bed-bugs  —  Brown  Turtle  Insect  —  White  Scaly  Coc- 
cus —  Pine-bug  —  Peach  Mildew  —  Woolly  Aphis  —  Aphis  — 
Thrips  —  Wood-lice  —  Insects  on  Fruit  Trees  —  Currant  Worm 

—  Rose-bug  —  Mildew  on  Chrysanthemum,  Grape,  Gooseberry 

—  Curculio  —  Kose  Mildew. 

Pages  1-18 

CHAPTER  II. 

SPRAYING  IN  FOREIGN  COUNTRIES. 
IN  FRANCE. 

Discursive  Trials  of  Fungicides  (page  19).  — Acetate  of  Potassium 

—  Sulphur  —  Downy  Mildew  of  the  Grape  in  France  —  Powdery 
Mildew  of  Grape  —  Powders  —  Iron    Sulphate  —  Plaster  — 
Fungivore  —  Pear  Diseases  —  Sulphuric  Acid  —  Copper  Sul- 
phate—  Spores  affected  by  Copper  Sulphate — Treatment  of 
Grape    Anthracnose  —  Copper    Sulphate    upon    Posts,   Tying 
Materials,  and  Stocks  —  Phenic  Acid  Emulsion. 

Origin  of  the  Bordeaux  Mixture  (page  24).  — An  Accidental  Dis- 
covery —  Early  Experiments  in  its  Use  —  Downy  Mildew  first 
systematically  treated  with  Bordeaux  Mixture  —  Other  Mate- 
rials tested  — First  Published  Formula  for  the  Bordeaux  Mix- 
ture —  Tomatoes  sprayed  with  Bordeaux  Mixture  for  Rot  — 
Recommendations  for  Treating  Potatoes  —  Treatment  of  Beaune 

—  Treatment  of  Millardet  —  Spraying  with  Simple  Solution  of 
Copper  Sulphate  —  Spraying  with  Milk  of  Lime  —  Treatments 
with  Powders. 

Origin  of  the  Ammoniated  Copper  Fungicides  and  Various  Com- 
binations (page  30).  — The  Use  of  Eau  Celeste  — A  Dilute 
Bordeaux  Mixture  —  Bouillies  Bourguignonnes. 

Powders  (page  32).  —  Podechard's  —  David's  —  Sulphosteatite  — 
Sulfatine. 

Perfection  of  Fungicides  (page  34).  —  Stock  Solutions  for  the 
Bordeaux  Mixture  —  Treatment  of  A.  Bouchard  —  Modified  Eau 
Celeste  —  Bouillie  Berrichonne  —  Treatments  for  Anthracnose  of 
Grapes  —  Tests  of  Fungicides  —  Grape  Black  Rot  in  France  — 
Bordeaux  Mixture  containing  some  Dissolved  Copper  —  Bor- 


Contents.  xiii 

deaux  Mixture  Celeste  —  Bordeaux  Mixture  and  Molasses  — 
Tests  of  Fungicides — Bordeaux  Mixture,  Various  Formulas 
and  Combinations  —  Treatments  for  Pear  Diseases. 
Insecticides  (page  50).  —  Soap  —  Alcohol  —  Aloes  —  Oxalic  Acid — 
Fichet's  Insecticide  —  Petroleum  —  Kerosene  Emulsion  —  Sul- 
phide of  Potassium  —  Benzine  —  Glue  —  Salicylic  Acid — Red 
Oxide  of  Mercury  —  Carbonate  of  Soda  —  Carbon  Bisulphide  — 
Pyrethrum. 

IN  ITALY  (page  53). 

Early  Applications  —  Adoption  of  French  Practices. 

IN    OTHER    CONTINENTAL    EUROPEAN    COUNTRIES    (page   53). 

Treatments  for  Oidium  Tuckeri  —  Introduction  of  the  Grape  Downy 
Mildew  —  Adoption  of  French  Practices  —  Present  Methods. 

IN    ENGLAND    (page    54). 

Slow  Adoption  of  the  French  Methods  —  Potassium  Sulphide  — 
Introduction  of  Copper  Sulphate  —  French  Journals  quoted  — 
Insecticides. 

IN  AUSTRALASIA  (page  57). 

Experiments  with  Fungicides  —  Introduction  of  French  and  Ameri- 
can Practices  —  Tasmanian  Spraying  Laws. 

Pages  19-58 

CHAPTER   III. 
SPRAYING  IN  AMERICA. 
IN  THE  UNITED  STATES. 

Spraying  for  Leaf- eating  Insects  and  the  Codlin-moth  (page  59). 
—  Appearance  of  the  Potato  Bug —  First  use  of  Paris  Green  — 
First  use  of  Paris  Green  for  the  Canker-worm — First  use  of 
Paris  Green  for  the  Codlin-moth  —  First  use  of  London  Purple 
— Introduction  from  England  —  Paris  Green  and  London  Pur- 
ple compared. 

Spraying  for  the  Curculio  (page  68) — The  Arsenites  and  the 
Curculio  —  Discussion  of  the  Value  of  Spraying  for  Curculio — 
New  York  Practices  —  Ohio  Practices. 


xiv  Contents. 

Other  Arsenites  (page  74).  —  Paris  Purple  —  English  Purple 
Poison  —  White  Arsenic  —  White  Arsenic  and  Lime. 

Caustic  and  Non-poisonous  Insecticides  (page  77). — Alkalies  — 
Quassia  —  Pyrethrum  —  Kerosene  —  Kerosene  Emulsions  — 
Cook's  Hard-soap  Emulsion  —  Cook's  Soft-soap  Emulsion  — 
Hubbard-Riley  Emulsion  —  Resin  Soaps  —  Resin  Washes  and 
Compounds. 

History  of  the  Fungicides  (page  87). — First  Materials  tested  — 
Hyposulphite  of  Soda  —  Sulphide  of  Lime  —  Sulphur  —  Meas- 
ures adopted  against  Grape  Diseases  before  the  Use  of  Copper 
Compounds — Publication  of  the  French  Discoveries  and  Recom- 
mendations. 

The  Warfare  against  the  Various  Fungous  Diseases  (page  92). 

—  First  Formulas  for  the  Copper  Sulphate  Solution,  Milk  of 
Lime,  Copper  Mixture  of  Gironde,  Podechard's  Powder,  Kero- 
sene Emulsions  —  Early  Treatments  of  Grapes  with  Copper 
Fungicides — Tests  of  Fungicides  —  Spraying  in  1887,  Formulas 
recommended  and  the  Plants  treated  —  Spraying  in   1888  — 
Spraying  in  1889  —  General  Treatment  of  Fruit  and  Nursery 
Stock  —  Combinations  of  Insecticides  and  Fungicides  —  Lime 
and  Arsenites —  Spraying  Greenhouse  Plants  —  Spraying  during 
1890  —  Improvements  in  Fungicides  —  Treatments  for  Potatoes 

—  Spraying  during  1891  —  Dilution  of  the  Bordeaux  Mixture  — 
Tests  of  the  Most  Promising  Fungicides  —  Spraying  since  1891 

—  Control  of  Black  Knot. 

IN  CANADA  (page  112). 

First  Adoption  of  Methods  recommended  in  the  United  States  — 
Spraying  in  Ontario  —  History  of  Spraying  in  Nova  Scotia  — 
Canadian  Publications. 

Pages  59-114 


CHAPTER  IV. 
THE  MATERIALS  AND  FORMULAS  USED  IN  SPRAYING. 

An  Alphabetical  List  of  the  Most  Important  Materials  used  in 
Spraying,  with  Directions  for  their  Preparation  and  Use. 

Pages  115-180 


Contents.  xv 

CHAPTER  V. 
SPRAYING  DEVICES  AND  MACHINERY. 

I.      HISTORY   OF   SYRINGES    AND  PDMPS    (page    181). 

Heath  Brooms  —  Watering-cans  —  Syringes  —  Fountain  Pumps  — 
Garden  Engines  —  Knapsack  Tanks  —  French  Knapsack  Pumps 
—  American  Knapsack  Pumps  —  Introduction  of  Barrel  Pumps 
— Types  of  Barrel  Pumps — Introduction  of  Power  Sprayers  — 
Spraying  with  Steam  —  Spraying  with  Gas  Power  —  Device  for 
Mixing  Kerosene  and  Water. 

ii.     EVOLUTION  OF  NOZZLES  (page  197). 

Three  Principles  the  Basis  of  all  Spray  Nozzles  —  The  Groups  of 
Nozzles  —  History  of  Each  Group  — Value  of  the  Nozzles  of 
Each  Group. 

III.      BELLOWS   AND   POWDER   GUNS    (page   204). 

Hand  Bellows  —  Power  Bellows. 

IV.       COMPARISON   OF   LIQUIDS   AND   POWDERS    (page  205). 

Advantages  of  Powders  —  Defects  of  Powders  —  Value  of  Liquids. 

V.       MERITS   OF   THE   VARIOUS   SPRAYING   DEVICES    (page   207). 

Materials  used  for  Making  Spraying  Machinery  —  Knapsack 
Pumps  —  Hand  Syringes  —  Bucket  Pumps  —  Barrel  Pumps  — 
Cylinders  —  Pistons  —  Handles  — Air  Chambers  —  Agitators  — 
Base-castings  —  Types  of  Barrel  Pumps  —  Horizontal-acting 
Pumps  —  Spraying  Eigs  and  Outfits  —  Orchard  Spray  ing  — 
Power  Machines  —  Spray  Nozzles  for  Different  Purposes  — 
Character  of  Sprays. 

Pages  181-224 

CHAPTER  VL 

THE  ACTION  OF  INSECTICIDES  AND  FUNGICIDES. 

The  Certainty  of  their  Action  —  The  Time  to  Spray  —  The  Manner 
to  Spray  —  Insecticide  defined  —  Fungicide  defined. 


xvi  Contents. 

i.     UPON  INSECTS  (page  227). 

Insecticides  destroying  by  Contact  —  Insecticides  destroying  when 
Eaten  —  Theoretical  Treatment  of  Insect  Enemies  —  Transfor- 
mations of  Insects. 

ii.     UPON  FUNGI  (page  228). 

Some  Characters  of  Fungi  —  Saprophytic  Fungi  —  Parasitic  Fungi 

—  Theoretical  Treatment  of  Fungous  Diseases. 

III.       UPON    THE    HOST-PLANT    (page    231). 

Not  Poisoning  the  Fruit  —  Healthfulness  of  Sprayed  Apples  and 
Grapes  —  Amounts  of  Copper  upon  Sprayed  Grapes  —  Effect  of 
Arsenic  upon  Foliage  —  Pasturing  Stock  in  Sprayed  Orchards 

—  Analysis  of  Grass  in  Sprayed  Orchards  —  Copper  Compounds 
upon  Foliage  —  Upon  the  Roots  of  Plants. 

.  iv.    UPON  THE  SOIL  (page  235). 

Analyses  of  Soils  treated  with  Copper  Compounds  and  the 
Arsenites  —  Condition  of  the  Arsenites  in  the  Soil  —  Action  of 
Copper  Solutions  upon  Soils  and  Plants. 

V.   UPON  THE  VALUE  OF  THE  CROP  (page  237). 

Necessity  of  Applications  upon  Certain  Crops  —  Keeping  Qualities 
of  Sprayed  Fruits  —  The  Benefits  derived  from  Spraying. 

Pages  225-238 

PART  II. 

SPECIFIC  DIRECTIONS  FOR    SPRAYING 
CULTIVATED  PLANTS. 

DESCRIPTION  AND  TREATMENT  OF  THE   MOST  IMPORTANT  INSECT 
AND  FUNGOUS  DISEASES  AFFECTING  CULTIVATED  PLANTS. 

Almond  —  Apple  —  Apricot  —  Asparagus  —  Aster  —  Balm  of 
Gilead  —  Barley  —  Bean  —  Bean,  Lima  —  Beet  —  Blackberry 

—  Cabbage  —  Carnation  —  Catalpa  —  Cauliflower  —  Celery  — 


Contents.  xvii 

Cherry  —  Chrysanthemum  —  Corn  —  Cotton  —  Cottonwood  — 
Cranberry  —  Cucumber  —  Currant  —  Dahlia  —  Eggplant  — 
Elm  —  Gooseberry  —  Grape  —  Greenhouse  Pests  —  Hollyhock 

—  Maple  —  Mignonette  —  Mosses  and  Lichens  —  Muskmelon  — 
Oats  —  Onion  —  Orange  —  Pansy  —  Parsley  —  Parsnip  —  Pea 

—  Peach  —  Pear  —  Plum  —  Potato  —  Privet  —  Pumpkin  — 
Quince  —  Radish — Raspberry  —  Rose  —  Shade  Trees,  Shrubs 

—  Spinach  —  Squash  —  Strawberry  —  Sweet  Potato  —  Sycamore 

—  Tobacco  —  Tomato  —  Turnip  —  Verbena  —  Violet  —  Water- 
melon —  Weigelia  —  Wheat  —  Willow. 

Pages  £39-374 

APPENDIX. 

A.       LAWS   REGARDING   THE    SPRAYING   OP  PLANTS    (page   375). 

In  California  —  In  Canada  —  In  Massachusetts  —  In  Michigan  — 
In  Oregon  —  In  Utah. 

B.    METRIC  SYSTEM  (page  382). 

Pages  375-383 

INDEX  (page  384). 


THE   SPRAYING   OF   PLANTS. 


PART  I. 

THE  HISTORY  AND  PRINCIPLES   OF 
SPRAYING. 


CHAPTER  I. 

EARLY  HISTORY  OF  LIQUID  APPLICATIONS. 

MAN'S  power  over  the  organisms  which  injure  cultivated 
plants  was  never  so  great  as  it  is  at  the  present  time.  One  by 
one  these  enemies  have  been  carefully  studied,  the  history  of 
their  lives  determined,  and  their  habits  observed.  Only  by 
understanding  them  thoroughly  can  proper  steps  be  taken  to 
check  their  ravages  in  the  most  economical  and  efficient  man- 
ner ;  yet  it  is  within  comparatively  recent  years  that  this  first 
step  was  taken  to  obtain  the  mastery  over  them.  Formerly, 
when  a  pest  injured  a  plant,  it  was  no  uncommon  practice  to 
apply  any  remedies  or  materials  that  came  to  hand,  regardless 
of  their  probable  efficiency.  It  was  not  generally  the  weakest 
point  of  the  organism  that  was  assailed.  In  many  cases  it  was 
not  even  the  proper  organism  which  was  held  responsible  for 
the  injury.  Nevertheless  many  valuable  discoveries  came  from 
these  varied  and  desultory  treatments,  and  some  of  the  remedies 
most  highly  prized  to-day  were  discovered  merely  by  chance, 
not  very  many  years  ago. 

Present  knowledge  and  methods  of  investigation,  largely 
founded  upon  this  experience,  enable  us  to  arrive  at  conclu- 

B  1 


^  The  'Spraying  of  Plants. 

"siohS  which^fromv  the-diitset,  are  founded  upon  a  sound  and 
logical  basis.  It  is  fortunate  that  this  is  the  case.  The  number 
of  the  enemies  of  cultivated  plants  is  either  now  more  numerous 
than  formerly,  or  the  attacks  are  much  more  energetic.  It  is 
undoubtedly  true  that  the  maladies  of  cultivated  plants  are 
much  more  widespread.  This  fact  is  mostly  due  to  the  greater 
food  supply,  and  to  the  greater  ease  with  which  most  of  the 
injurious  forms  can  pass  from  one  part  of  the  country  to  an- 
other, because  the  cultivated  areas  lie  so  close  together.  If  a 
plant  is  grown  to  any  considerable  extent,  it  is  easy  for  its  ene- 
mies to  spread  over  the  entire  region  in  which  it  is  cultivated. 
Physical  barriers  are  almost  without  value  in  checking  this 
spreading  of  disease.  The  ocean  is  only  a  partial  exception, 
since  such  close  means  of  communication  have  been  established 
between  all  parts  of  the  globe  that  this  obstacle  is  now  of  little 
avail.  Some  diseases  have  not  yet  been  able  to  overpass  it,  but 
as  it  has  proved  of  little  hindrance  in  so  many  cases,  it  is  probable 
that  ultimately  the  enemies  and  diseases  of  plants  will  be  as 
widespread  as  are  the  plants  upon  which  they  flourish.  Weedy 
plants,  insects,  and  possibly  also  fungi,  are  frequently  more 
destructive  in  a  new  country  than  in  their  old  home.  They  are 
freed  from  the  enemies  or  conditions  which  formerly  kept  them 
in  check,  and  in  some  cases  they  are  the  cause  of  very  serious  dis- 
turbance, although  originally  they  may  not  have  been  markedly 
destructive. 

Farmers  and  fruit  growers  cannot  fence  out  the  many  forms 
of  insects  and  fungi  which  live  upon  their  crops  and  which  are 
as  anxious  for  a  harvest  as  the  grower  is.  It  is  a  fight  between 
the  grower  and  the  pest,  and  it  must  be  admitted  that  the  latter 
has  generally  had  the  best  of  the  battle.  The  farmer  has  not 
been  properly  equipped.  He  has  often  had  invisible  foes  to 
contend  with,  —  foes  which  he  did  not  understand,  and  which 
he  could  not  assail.  It  frequently  occurred  that  an  entire  crop 
was  ruined  in  a  day  or  two,  and  the  cause  remained  unseen  and 
unknown ;  and  even  if  it  was  visible,  almost  the  only  remedy 
upon  which  the  grower  could  rely  with  certainty  was  mere 
force,  first  catching  the  pest  and  then  destroying  it.  As  this 
could  be  done  with  profit  only  in  rare  cases,  it  was  little  better 
than  no  remedy,  and  the  general  result  was  that  the  insect  or 
the  fungus  obtained  an  ample  supply  of  nourishment,  and  the 


Early  History  of  Liquid  Applications.  3 

grower  took  what  was  left.  Indeed,  this  method  is  still  fol- 
lowed by  many  cultivators,  but  it  is  not  the  safest,  nor  is  it  the 
most  profitable  one. 

The  best  is  generally  the  most  profitable  commodity,  and  the 
poorest  is  the  least  so ;  and  the  grower  of  to-day  has  it  in  his 
power  to  produce  the  best.  It  rests  entirely  with  him  whether 
his  apples  shall  be  wormy  or  not,  whether  his  trees  shall  retain 
their  foliage  or  lose  it  from  disease.  There  are  few  evils  that 
affect  his  crops  which  he  cannot  control,  in  many  cases  almost 
absolutely.  Only  a  few  diseases  remain  which  still  refuse  to 
submit  to  treatment,  but  the  number  is  rapidly  decreasing,  and 
the  time  will  come  when  these  also  will  disclose  some  vulnerable 
point  which  will  allow  of  their  destruction. 

Foremost  among  the  operations  by  means  of  which  cultivated 
plants  are  protected  from  their  enemies,  is  spraying.  This  con- 
sists in  throwing  upon  plants  any  fluids,  or  semi-fluids,  in  the 
form  of  a  fine  rain  or  mist.  It  rests  upon  the  general  principle 
of  covering  the  plants,  or  the  parts  of  plants  to  be  protected,  with 
a  thin  but  uniform  layer  of  some  material  that  is  poisonous, 
caustic,  or  offensive  to  the  organism  which  it  is  desired  to  de- 
stroy. The  word  "  spraying,"  as  understood  in  this  connection, 
has  not  been  in  general  use  more  than  ten  or  fifteen  years,  for 
the  operation  previous  to  this  time  was  practiced  only  to  a  very 
limited  extent.  It  was  then  referred  to  as  "  syringing,"  from 
the  fact  that  hand  syringes  were  generally  used  as  a  means  of 
making  the  applications.  This  term  is  still  in  common  use 
among  florists  and  gardeners,  whose  daily  duty  it  is  to  throw 
water  upon  their  plants  either  for  the  purpose  of  promoting 
growth,  or  in  order  to  keep  them  free  from  foreign  matter, 
such  as  insects  or  dust.  It  is  essentially  a  term  which,  in  this 
country,  is  used  in  connection  with  plants  grown  wholly  or 
partially  in  a  greenhouse  or  in  some  similar  structure.  Spray- 
ing, on  the  other  hand,  is  a  term  now  used  by  farmers  and 
fruit-growers  to  designate  a  similar  operation,  but  the  plants 
treated  are  grown  entirely  out  of  doors,  and  pure  water  is 
rarely  used.  The  operation  of  both  syringing  and  spraying  is, 
however,  the  same ;  namely,  the  throwing  of  liquids,  more  or 
less  finely  divided,  upon  plants  or  other  objects. 

It  is  impossible  to  tell  when  plants  were  first  syringed.  It 
is  very  probable  that  the  value  of  the  operation  was  understood 


4  The  Spraying  of  Plants. 

as  soon  as  the  cultivation  of  plants  began  to  attract  serious 
attention.  The  immediate  causes  which  led  to  the  practice 
were  undoubtedly  the  same  as  those  now  existing.  Foliage 
almost  invariably  looks  brighter  and  fresher  when  wet,  and  one 
instinctively  feels  that  if  the  appearance  of  a  plant  is  improved 
by  a  certain  operation,  the  general  health  of  the  plant  is 
improved  to  an  equal  degree.  The  removal  of  insects  or  any 
injurious  substances  would  have  a  similar  effect,  and  all  good 
gardeners  would  feel  a  temptation  to  improve  their  plants  in  this 
simple  way. 

Insects  and  diseases  have  unquestionably  troubled  cultivators 
from  the  time  plants  were  first  grown.  Remedies  would  natu- 
rally be  sought,  and  it  appears  that  these  older  gardeners  were 
controlled  by  the  same  feeling  which  even  to-day  often  mani- 
fests itself  in  connection  with  the  taking  of  medicine  :  the 
worse  the  drug  smells  or  tastes,  the  more  good  it  is  supposed  to 
do.  Early  in  the  seventeenth  century  Parkinson  advised  the  use 
of  vinegar  to  prevent  canker  on  trees,  and  the  recommendation 
was  supposed  to  rest  upon  a  very  firm  foundation.1  One  old 
record  2  giving  instructions  for  making  liquid  applications  of  an 
insecticide  reads  as  follows:  "  Cantharides  (Cantarides)  are 
flies  which  attach  themselves  to  the  branches  near  the  upper  parts 
of  trees,  especially  on  the  ash.  They  may  be  destroyed  by 
pouring  or  throwing  on  the  tops  of  the  trees,  by  means  of  a 
small  pump,  water  in  which  has  been  boiled  some  rue."  Ruta 
graveolens  is  probably  meant.  This  herb  has  a  strong,  heavy, 
and  very  disagreeable  odor,  and  a  sharp,  bitter  taste.  If  such 
qualities  make  a  plant  a  good  insecticide,  rue  should  be  one  of 
our  most  valuable  remedies.  It  seems  very  probable  that  the 
idea  of  selecting  materials  which  are  offensive  to  the  senses  was 
uppermost  in  the  minds  of  those  who  first  had  occasion  to  use 
them,  for  most  of  the  earlier  substances  recommended  are  of 


1  John  Parkinson,  "  Paradisus,"  The  Ordering  of  the  Orchard,  Chap.  viii.  550. 
1629 :  "  The  canker  is  a  shrewd  disease  when  it  happeneth  to  a  tree ;  for  it  will 
eate  the  barke  round,  and  so  kill  the  very  heart  in  a  little  space.  It  must  be 
looked  into  in  time  before  it  hath  runne  too  farre  ;  most  men  doe  wholly  cut  away 
as  much  as  is  fretted  with  the  canker,  and  then  dresse  it,  or  wet  it  with  vinegar  or 
cowes  pisse,  or  cowes  dung  and  urine,  &c.  untill  it  be  destroyed,  and  after  healed 
againe  with  your  salve  before  appointed." 

8  "La  Theorie  du  Jardinage,"  166,  1711.  See  also  Deane,  "The  Newengland 
Farmer,"  1T7-184. 


Early  History  of  Liquid  Applications.  5 

this  character.  A  great  variety  of  materials  must  have  been 
tested  again  and  again  by  various  persons  independently  of  each 
other.  Those  materials  which  possessed  real  or  imaginary  reme- 
dial values,  or  which  from  their  very  nature  appeared  to  possess 
them,  remained  in  use  until  something  that  promised  better 
could  be  found.  Thus  it  came  that  at  the  close  of  the  eigh- 
teenth century,  and  early  in  the  nineteenth,  the  number  of 
things  recommended  against  various  diseases  was  large,  and 
some  of  the  compounds  possessed  considerable  insecticidal 
value.  The  following  examples  may  here  be  cited : 

"  In  the  year  1763,  there  appeared  in  the  papers  of  Marseilles 
a  remedy  for  plant-lice.  The  applications  should  be  made  by 
means  of  a  small  tin  syringe  having  a  nose  pierced  by  about 
one  thousand  holes.  The  instrument  is  filled  with  water  in 
which  lime  has  been  slaked,  previously  mixing  with  the  clear 
liquid  some  bad  tobacco,  finely  powdered  ;  this  should  be  used 
at  the  rate  of  a  handful  to  two  liters  of  the  liquid.  The  trees 
are  syringed  with  the  mixture,  and  although  the  foliage  remains 
uninjured  the  pests  are  destroyed.  But  after  four  or  five  days 
the  trees  should  be  again  syringed,  using  clear  water."  * 

"  But  many  of  the  plant-lice  may  be  destroyed  by  passing  the 
leaves  upon  which  they  are  found  between  two  sponges  wet 
with  tobacco  water.  Ground  tobacco  powder  spread  upon  the 
insects  will  kill  them  instantly.  One  may  also  use  with  it  the 
water  of  slaked  lime  or  of  strong  soap,  soot,  sage,  hyssop,  worm- 
wood, and  other  bitter  or  strong-smelling  herbs.  Soot,  lime, 
and  soap  have  the  disadvantage  of  staining  the  leaves,  fruits, 
and  the  plants  to  which  they  are  applied.  Tobacco  and  worm- 
wood leave  small  particles  upon  the  portions  treated.  Other 
materials  are  often  without  value.  Tansy,  hellebore,  rue,  leek, 
bitter  gourd,  and  long  pepper  have  the  disadvantages  men- 
tioned above.  Petroleum,  turpentine,  and  other  oils  are  also 
recommended ;  but  care  must  be  taken  in  their  use,  since  they 
also  act  upon  the  plants,  making  them  sick  or  even  killing 
them."  2 

"  First  wet  the  trees  infested  with  lice,  then  rub  flowers  of 
sulphur  upon  the  insects  and  it  will  cause  them  all  to  burst."  8 

1  J.  A.  E.  Goeze,  "  Geschichte  einiger  schadlichen  Insecten."  Leipzig,  1787, 
166. 

*  Ibid.  164.  » Ibid.  168. 


6  The  Spraying  of  Plants. 

Forsyth  in  179 1,1  gave  directions  for  the  preparation  of  a  com- 
pound  which  became  generally  known  as  "  Forsyth's  Composi- 
tion." The  ingredients  were  apparently  standard  remedies  at 
this  time,  and  they  persisted  long  after  his  composition  went 
out  of  use.  It  was  made  as  follows  : 

"Take  one  bushel  fresh  cow  dung,  one-half  bushel  lime  rub- 
bish from  old  buildings,  one-half  bushel  wood  ashes,  one-six- 
teenth bushel  pit  or  river  sand.  The  last  three  are  to  be  sifted 
fine  before  they  are  mixed.  Then  work  them  well  together  with 
a  spade,  and  afterward  with  a  wooden  beater  until  the  stuff  is 
very  smooth,  like  fine  plaster  used  for  the  ceilings  of  rooms." 

Soap-suds  or  urine  was  used  to  make  the  composition  of  the 
consistency  of  plaster  or  paint. 

After  being  applied  it  was  covered  with  a  sifting  of  powder 
made  of  "  dry  powder  of  wood  ashes,  mixed  with  the  sixth  part 
of  the  same  quantity  of  the  ashes  of  burnt  bones." 

This  composition  was  recommended  to  cure  disease,  defects, 
and  injuries  of  plants.  It  was  held  to  be  particularly  valuable 
in  promoting  the  healing  of  wounds,  and  was  commonly  used  to 
fill  cavities  in  trees. 

Early  in  the  history  of  the  treatment  of  plant  diseases,  paints 
and  washes  were  in  general  use.  They  were  applied  by  means 
of  brushes,  or  the  plants  were  actually  washed  with  a  rag  or 
sponge,  so  that  they  were  very  thoroughly  cleaned.  This  practice 
is  by  no  means  out  of  date,  for  it  is  still  one  of  the  regular  duties 
in  good  greenhouse  management  to  wash  many  of  the  plants  in 
order  to  keep  the  foliage  clean  and  healthy.  Soap  or  some 
similar  substance  is  still  generally  added  to  the  water,  as  was 
formerly  done.  This  alkali  could  always  be  readily  obtained, 
and  as  it  possesses  decided  merit  as  a  destroyer  of  certain  in- 
sects, it  was  at  a  very  early  day  regarded  as  a  valuable  remedy. 

We  have  another  interesting  note  in  the  following  extract 
in  which  the  destruction  of  the  canker-worm  is  desired : 2 

"  There  are  several  experiments  I  could  wish  to  have  tried, 
for  subduing  these  insects :  Such  as  burning  brimstone  under 
the  trees  in  a  calm  time ;  —  or  piling  dry  ashes,  or  dry,  loose 

1  Oath  regarding  the  correctness  of  the  directions  was  made  at  the  Land  Eevenue 
Office,  in  Scotland  Yard,  the  eleventh  day  of  May,  1791. 

9  Samuel  Deane,  D.D.  (vice-president  of  Bowdoin  College),  "  The  Newengland 
Farmer,  or  Georgical  Dictionary,"  second  edition,  179T. 


Early  History  of  Liquid  Applications.  1 

sand  round  the  roots  of  trees  in  the  spring ;  —  or  throwing 
powdered  quicklime,  or  soot,  over  the  trees  when  they  are  wet ; 
—  or  sprinkling  them,  about  the  beginning  of  June,  with  sea 
water,  or  water  in  which  wormwood,  or  walnut  leaves,  have 
been  boiled ;  —  or  with  an  infusion  of  elder,  from  which  I 
should  entertain  some  hope  of  success.  The  liquid  may  be 
safely  applied  to  all  the  parts  of  a  tree  by  a  large  wooden  syr- 
inge, or  squirt. 

"  I  should  suppose  that  the  best  time  for  making  trial  of  these 
methods  would  be  soon  after  the  worms  are  hatched:  for  at 
that  stage  of  their  existence  they  are  tender,  and  the  more 
easily  killed.  Sometimes  a  frost  happening  at  this  season  has 
destroyed  them.  This  I  am  told  was  the  case  in  some  places 
in  the  year  1794." 

Forsyth  1  recommended  the  following  mixture  for  the  de- 
struction of  aphis : 

Unslaked  lime *  peck. 

Water 32  gallons. 

Allow  this  to  stand  three  or  four  days,  stirring  two  or  three 
times  per  day.  It  wras  applied  by  means  of  a  syringe.  He 
recommended  2  the  same  mixture  for  the  destruction  of  acarus, 
or  red  spider,  but  said  that  pure  water  would  also  answer  the 
purpose.  For  plants  in  hothouses  the  use  of  pure  water  alone 
was  advised.  Against  insects  on  melons,  however,  he  said  3  that 
the  plants  should  first  be  washed  with  water,  and  then  again 
washed  with  a  mixture  of  urine  and  soap-suds,  using  a  rag. 
It  is  also  stated 4  that  several  English  nurserymen  used  train- 
[whale-]  oil  against  coccus,  or  scale  insects  on  plants.  It  was 
applied  with  a  brush,  but  the  author  claims  that  it  was  not  an 
efficient  remedy.  Nevertheless  it  was  extensively  used  in  some 
parts  of  England. 

During  the  early  years  of  this  century  a  great  many  sub- 
stances were  recommended  both  in  this  country  and  in  Europe 
for  the  destruction  of  the  enemies  of  cultivated  plants. 
Mention5  is  made  of  the  following  articles  which  were  to 

1  William  Forsyth,  "  A  Treatise  on  Culture  and  Management  of  Fruit  Trees," 
American  edition  edited  by  William  Cobbett,  1802,  173. 

2  Ibid.  174.  «  Ibid.  176.  «  Ibid.  179. 
«  J.  Thacher,  M.P.,  "  American  Orcbardist,"  1822,  104. 


8  The  Spraying  of  Plants. 

be  used  against  the  apple-tree  borer,  an  insect  that  is  desig- 
nated as  a  "  pernicious  reptile  "  by  the  author.  After  digging 
out  the  borer,  fill  the  cavity  about  the  base  of  the  tree  with 
"  flax  rubbish,  sea-weed,  ashes,  lime,  sea-shells,  sea-sand,  mortar 
rubbish,  clay,  tanner's  bark,  leather  scraps,  etc."  I  can  find 
no  record  of  careful  experiments  having  been  made  with  these 
articles,  and  it  is  not  improbable  that  some  of  them  were 
recommended  without  actual  trial,  as  is  sometimes  done  even 
to  this  day,  simply  on  the  ground  that  the  remedy  "ought" 
to  be  of  value.  It  is  also  stated,1  quoting  from  the  "  Massachu- 
setts Agricultural  Reports,"  that  Josiah  Knapp,  of  Boston,  in 
1814,  used  air-slaked  lime  with  success  against  the  canker-worm. 
He  applied  it  thickly  about  the  base  of  the  tree.  Later  experi- 
ments have  shown  that  this  is  of  little  benefit  in  checking  the 
ravages  of  the  insect.  The  use  of  air-slaked  lime  is  said  2  to 
have  been  successful  in  the  destruction  of  slugs  found  on  the  foli- 
age of  fruit  trees,  and  this  is  still  one  of  the  best  remedies  we 
possess.  Tar  water  also  proved  to  have  the  power  of  instantly 
killing  the  slugs  with  which  it  came  in  contact.  It  was  pre- 
pared by  pouring  water  on  tar  and  allowing  it  to  stand  for 
two  or  three  days.  This  gave  a  strong  infusion  and  was  said 
to  be  very  effective. 

Several  remedies  against  caterpillars  are  also  mentioned.8 
"  It  is  asserted  "  that  spirits  of  turpentine,  or  common  fish-oil, 
has  the  power  of  penetrating  through  the  web  made  by  these 
insects  and  they  are  killed  when  the  liquid  comes  in  contact 
with  their  bodies.  Mr.  Yates,  of  Albany,  N.Y.,  made  a  mix- 
ture which  well  illustrates  the  variety  of  materials  used  during 
this  period : 

Wormwood 1  handful. 

Eue 1 

Virginia  tobacco 2  handfuls. 

Water 2  pailfuls. 

Boil  the  herbs  in  the  water  for  half  an  hour,  strain  the 
liquid,  and  it  is  then  ready  to  be  applied.  Yates  also  said  that 
if  sufficient  tobacco  is  used  alone,  it  will  answer  the  same  pur- 
pose as  the  above,  but  not  so  well. 

i  J.  Thacher,  M.D.,  "  American  Orchardist,"  1822,  92. 
»  Ibid.  107.  »  Ibid.  96. 


Early  History  of  Liquid  Applications.  9 

Reference  is  also  made  l  to  some  experiments  of  E.  Perley  to 
combat  scale  insects  on  trees.  He  found,  after  trying  many  sub- 
stances, that  the  most  effectual  way  of  removing  scale  insects 
from  trees  was  to  wash  them  with  lye,  or  brine.  Lime  could  be 
used  with  the  lye  to  advantage.  The  brine  was  made  by  using 

Common  salt 1  quart. 

Water 2  gallons. 

This  could  be  applied  as  soon  as  the  salt  was  entirely  dissolved. 

Thacher2  regarded  train-oil  as  a  very  powerful  insecticide 
against  lice,  but  discouraged  its  use  on  account  of  its  glutinous 
character,  it  being  on  this  account  harmful  to  trees. 

Clay  paint  was  perhaps  one  of  the  first  remedies  to  be  ap- 
plied to  plants.  Several  factors  would  encourage  its  use  ;  among 
others  may  be  mentioned  the  ease  of  its  preparation,  its  cheap- 
ness, and  its  adhesive  properties.  When  properly  used  it  forms 
a  thin,  dense  coating  over  the  parts  to  which  it  is  applied,  and 
it  has  the  appearance  of  granting  almost  perfect  protection  to 
the  part  covered.  The  Caledonian  Horticultural  Society,  of 
Scotland,  recommended  3  its  use,  and,  in  fact,  its  application  has 
been  very  generally  advised.  It  has  also  formed  the  basis  of  many 
mixtures  and  only  with  the  appearance  of  the  remedies  now  in 
common  use  has  it  fallen  from  favor.  Only  the  purest  clay 
obtainable  was  selected,  and  it  was  generally  strained  so  that 
the  coarser  particles  might  be  removed. 

A  solution  which  appears  to  have  been  in  common  use  for 
the  destruction  of  bed-bugs  was  also  said  4  to  be  valuable  as  a 
remedy  for  canker.  "  Canker  "  is  an  indefinite  term  which  was 
employed  to  denote  almost  any  disease  of  the  stems  or  trunks 
of  plants,  whose  origin  was  not  understood;  the  injury  may 
have  been  caused  by  insects  or  by  fungi,  or  any  of  several  other 
causes.  Whenever  death  and  decay  overtook  any  part  of  the 
stem,  it  was  generally  termed  canker.  The  solution  which 
would  cure  or  check  the  disease  was  made  by  taking 

Corrosive  sublimate 1  drachm. 

Spirits  (alcohol) 1  gill. 

Soft  water 4  quarts. 

1  J.  Thacher,  M.D.,  "American  Orchardist,"  1322,  109. 

*  Ibid.  108.  »  Ibid,  second  edition,  1825,  79. 

*  "Th«  Practical  American  Gardener,"  Baltimore,  1822,  170. 


10  The  Spraying  of  Plants. 

The  corrosive  sublimate  was  first  dissolved  in  the  spirits, 
and  then  this  solution  was  added  to  the  water.  It  was  said  to 
kill  the  eggs  as  well  as  the  insects  with  which  it  came  in  con- 
tact ;  and  although  long  in  use  it  still  stands  as  one  of  the 
most  valuable  agents  for  the  destruction  of  some  insects  which 
are  not  closely  connected  with  horticultural  products.  It  also 
possesses1  the  power  of  destroying  the  "brown  turtle  [scale] 
insect,  white  scaly  coccus,  pine  bug  [mealy-bug?],  and  red 
spider."  A  decoction  of  tobacco  was  pronounced  to  be  excel- 
lent for  the  removal  of  aphis,  thrips,  and  wood-lice. 

Although  fungous  diseases  are  rarely  mentioned  in  these  early 
writings,  their  suppression  was  nevertheless  attempted.  John 
Robertson,  in  a  paper  read  Nov.  20,  1821,  before  the  London 
Horticultural  Society,2  said  sulphur  was  the  only  specific  remedy 
that  could  be  named  for  the  treatment  of  mildew  on  peaches. 
It  should  be  mixed  with  soap-suds  and  then  be  applied  by  dash- 
ing it  violently  against  the  trees  by  means  of  a  rose  syringe.  It 
was  necessary  to  sprinkle  all  parts  of  the  tree  with  the  mixture 
to  be  certain  of  success.  Sulphur  is  to-day  one  of  our  standard 
remedies  against  such  mildews,  and  it  seems  that  no  other  sub- 
stance will  soon  supersede  it. 

William  Cobbett  mentions  3  some  instructions  for  the  treat- 
ment of  the  cotton  blight  (woolly  aphis)  which,  if  well  carried 
out,  would  certainly  dislodge  the  pest.  He  directs  that  where 
these  insects  are  found,  to  wash  "  the  place  well  with  some- 
thing strong,  such  as  tobacco  juice.  The  potato,  which  some 
people  look  upon  as  so  nutritious,  very  nearly  poisons  the 
water  in  which  it  is  boiled;  and  an  Irish  gentleman  once  told 
me  that  that  water  would  cure  the  cotton  blight.  Rubbing 
the  part  with  mercurial  ointment  will  certainly  do  it." 

The  idea  that  "  something  strong  "  was  necessary  to  dislodge 
the  enemy  was  still,  apparently,  the  leading  thought,  and 
nearly  everything  that  could  be  said  to  possess  this  desired 
quality  was  probably  given  a  chance  to  prove  its  merits  at  one 
time  or  another.  Thomas  Fessenden  gives  4  an  interesting  list 
of  a  few  of  the  materials  which  were  supposed  to  possess  the 

1  "  The  Practical  American  Gardener,"  Baltimore,  1822,  397. 

a  Trans.  London  Hort.  Soc.,  Vols.  i.-v.  1824,  178. 

8  Cobbett,  "The  English  Gardener,"  1829,  first  English  edition,  289. 

*  Fessenden,  "New  American  Gardener,"  sixth  edition,  1832,  169. 


Early  History  of  Liquid  Applications.         11 

strength  necessary  to  overcome  the  organism  against  which 
they  were  applied.  He  writes  as  follows : 

"  Insects  may  be  annoyed,  and  oftentimes  their  complete 
destruction  effected,  by  sprinkling  over  them,  by  means  of 
a  syringe,  watering-pot,  or  garden  engine,  simple  water,  soap- 
suds, tobacco  water,  decoctions  of  elder,  —  especially  the  dwarf 
kind,  —  of  walnut  leaves,  bitter  and  acrid  herbs,  pepper,  lye  of 
wood  ashes,  or  solutions  of  pot  and  pearl  ashes,  water  impreg- 
nated with  salt,  tar,  turpentine,  etc.;  or  they  may  be  dusted 
with  sulphur,  quicklime,  and  other  acrid  substances."  An- 
other article,  one  mentioned  by  Lindley,1  is  vinegar,  and  he 
says  that  it  is  of  considerable  value  for  destroying  insects. 

With  such  a  battery  of  powerful  materials  directed  against 
them,  it  is  a  wonder  that  so  many  insects  we  now  have  to  con- 
tend with  should  still  exist.  The  very  number  of  the  materials 
named  is  an  indication  of  weakness ;  for  if  any  of  them  had 
really  possessed  very  decided  merit,  there  would  have  been  no 
necessity  for  the  existence  of  the  rest.  Some  of  them  are  really 
valuable,  and  are  in  use  at  the  present  time,  yet  it  is  true  that 
we  are  still  on  the  lookout  for  something  which  is  superior  to 
the  remedies  now  at  hand. 

The  value  of  hot  water  as  an  insecticide  has  long  been 
known.  Fessenden  quotes2  Loudon  as  saying:  "Saline  sub- 
stances mixed  with  water  are  injurious  to  most  insects  with 
tender  skins,  as  worms  and  slugs ;  and  hot  water,  when  it  can 
be  applied  without  injuring  vegetation,  is  equally,  if  not  more 
powerfully,  injurious.  AVater  heated  to  120  or  130  degrees 
will  not  injure  plants  whose  leaves  are  expanded  and  in  some 
degree  hardened ;  and  water  at  200  degrees  or  upwards  may  be 
poured  over  leafless  plants."  In  a  later  work,3  Loudon  says: 
"Mr.  Swainson  advises  for  the  destruction  of  the  aphis  'the 
application  of  warm  water,  sufficiently  hot  to  destroy  aphis 
without  injuring  the  trees :  more  will  be  thus  destroyed  than 
either  by  repeated  application  of  the  syringe  or  by  the  use  of 
tobacco  water.  .  .  .  Two  or  three  applications  of  warm  water 
will  destroy  nearly  all  the  insects.'"  The  remedy  was  also 
frequently  mentioned  in  horticultural  journals. 

1  Lindley,  "  Guide  to  the  Orchard  and  Kitchen  Garden,"  1831,  509. 

2  Fessenden,  "Xew  American  Gardener,"  sixth  edition,  1S32,  169. 
•  "Loudon's  Encyclopaedia  of  Gardening,"  1878,  795. 


12  The  Spraying  of  Plants. 

Dr.  William  Kenrick1  speaks  of  aloes  and  cayenne  pepper, 
among  other  materials,  as  being  effective  in  the  treatment  of 
aphis,  but  their  use  never  became  very  general.  He  also  gives  2 
a  formula  for  the  destruction  of  a  white,  mealy  insect : 

Quicklime £  peck. 

Flowers  of  sulphur £  pound. 

Lampblack I     " 

Mix  all  in  as  much  boiling  water  as  will  make  a  thick  paste, 
and  apply  warm.  The  lime  and  the  sulphur  are  probably  the 
most  active  portions  of  the  mixture.  Although  lampblack  is 
here  mixed  with  them,  these  two  substances,  when  used  to- 
gether in  water,  already  formed  one  of  the  most  important  and 
valuable  remedies  in  use  against  the  various  mildews  which 
attack  plants.  The  same  writer  gives  8  the  following  formula, 
in  which  sulphur  and  quicklime  are  recommended  for  checking 
mildew  on  grapes : 

Sulphur \  pint. 

Quicklime piece  size  of  the  fist. 

Water  (boiling) 2  gallons. 

When  cool,  dilute  with  cold  water,  and  allow  the  solid  mate- 
rial to  settle.  Then  draw  off  the  clear  liquid,  and  pour  it  into 
a  barrel.  The  barrel  is  then  filled  with  water,  and  the  mixture 
is  ready  for  use.  A  modification  of  this  formula  eventuallv 
came  to  be  a  standard  preparation  for  the  treatment  of  mil- 
dews; but  during  this  period  the  substances  were  used  in 
varying  proportions,  and  generally  other  ingredients  were 
mixed  with  them. 

John  Mearns  made  a  composition,  which  was  suggested  to 
him  by  Thomas  Andrew  Knight,  at  that  time  president  of  the 
London  Horticultural  Society.4  In  a  paper  read  in  1835,  he 
gave  directions  for  making  this  preparation : 

Strongest  farmyard  drainage 1  gallon. 

Soft  soap 1  pound. 

Flowers  of  brimstone " 

i  William  Kenrick,  "The  New  American  Orchardist,"  1833.  Introduction 
xxxiii. 

8  Ibid,  xxxvi.  s  /j^.  323. 

*  Trans.  London  Hort.  Soc.  second  series,  1842,  Vol.  ii.  89. 


Early  History  of  Liquid  Applications.         13 

These  ingredients  were  well  mixed  together  and  were  stirred 
three  or  four  times  a  day.  This  was  done  for  several  days,  and 
then  some  finely  sifted  quicklime  was  added,  until  the  whole 
assumed  the  consistency  of  paint.  Mearns  said  the  farmyard 
drainage  might  be  replaced  by  tobacco  juice,  and  the  lime  by  soot. 
This  mixture  was  recommended  for  the  destruction  of  insects. 

The  use  of  pungent  and  acrid  herbs  long  continued  to  be 
recommended  for  the  same  purpose.  T.  Bridgeman,  among 
other  remedies,  speaks  l  of  burdock  leaves  as  being  effective  in 
preventing  injury  from  the  attacks  of  the  "turnip  and  cabbage 
fly."  He  recommends  preparing  hogsheads  full  of  the  infusions 
of  this  and  other  herbs,  and  then  sprinkling  the  plants  with 
the  liquor.  For  the  annoyance  or  destruction  of  insects  on  fruit 
trees  he  advises  the  use  of  decoctions  made  of  walnut  leaves,  as 
well  as  those  of  tobacco  and  elder;  the  use  of  pepper,  soot, 
sulphur,  and  similar  substances  are  also  mentioned  as  having 
value,  their  action  being  perhaps  more  particularly  the  annoy- 
ance of  the  pest  than  its  destruction. 

White  hellebore  was  also  commonly  recommended  as  early 
as  1842,  although  it  did  not  prove  of  value  in  the  hands  of 
all  growers.  It  was  used  particularly  to  destroy  worms  on 
gooseberry  plants,  and  was  applied  in  the  form  of  a  powder  or 
in  pure  water,  or  when  mixed  with  soap-suds.2  It  does  not 
appear  to  have  been  used  to  any  considerable  extent  in  America 
until  after  the  introduction  of  this  gooseberry  saw-fly,  or  as 
it  is  here  known,  the  imported  currant  worm,  which  occurred 
sometime  before  1858,  at  which  time  its  presence  was  first 
noticed.  Joseph  Harris  is  said  to  have  been  the  first  to  recom- 
mend the  use  of  hellebore  in  America,3  after  he  had  been  using 
it  successfully  for  four  years.  P.  Barry  used  it  mixed  with 
water,  and  applied  the  liquid  to  his  plants  by  means  of  a 
syringe,  one-half  pound  being  used  in  a  pail  of  water. 

A  rather  unusual  solution  was  used  by  J.  Murray 4  against 
mildew  on  peach  trees.  He  applied 

Sulphur 2  pounds. 

Alcohol 1  quart. 

1  Bridgeman,  "  The  Young  Gardener's  Assistant,"  seventh  edition,  1837,  11 

*  Gardener?  Chronicle,  1S42,  June  18,  397. 
8  Country  Gentleman,  1865,  June  29,  413. 

*  Gardeners'  Chronicle,  1841,  Aug.  21,  550. 


14  The  Spraying  of  Plants. 

The  trees  were  thoroughly  painted  with  this  when  the  buds 
were  swelling.  He  asserts  that  he  used  the  mixture  for  twenty 
years,  so  it  must  have  been  very  effective  in  his  hands.  Nitre 
was  also  applied  for  mildew  on  roses.1  It  was  prepared  by  using 

Nitre 1  ounce. 

Water 1  gallon. 

In  December,  1844,  its  use  on  chrysanthemums  for  mildew 
was  also  mentioned. 

On  June  13,  1840,  the  Massachusetts  Horticultural  Society 
offered  a  premium  for  the  most  cheap  and  effective  mode  of 
destroying  the  rose-bug.  David  Haggerston,  of  Watertown, 
Mass.,  was  awarded  a  premium  of  $120  on  March  5,  1842,  after 
his  remedy  had  been  thoroughly  tested  by  a  committee.  The 
material  which  he  employed  was  whale-oil  soap,  used  at  the 
rate  of 

Whale-oil  soap 2  pounds. 

Water 15  gallons. 

He  said  the  strength  of  the  soap  varied  and  this  would  re- 
quire a  change  in  the  above  formula  in  certain  cases.  He  con- 
tended that  this  is  an  effectual  remedy  for  other  troublesome 
insects ;  as  the  thrips  or  vine  f retter,  the  aphis  or  plant-louse, 
the  black  fly  that  infests  the  young  shoots  of  the  cherry,  the 
red  spider,  and  other  insects.  He  also  asserted  that  it  would 
destroy  mildew  on  peaches,  grapes,  and  gooseberries,  if  weak 
solutions  were  used.  Whale-oil  soap  is  to-day  so  well  known 
and  so  generally  used  against  insect  enemies  that  it  is  scarcely 
necessary  to  say  that  many  of  the  statements  of  Haggerston  are 
just.2 

London  has  recorded  8  several  interesting  recipes  that  show 
how  complex  were  many  of  the  mixtures  recommended.  Some 
of  them  contained  so  many  ingredients  that  it  would  seem  as 
if  any  evil  that  plants  are  heir  to  would  be  reached  by  at  least 
one  of  them.  NicoPs  recipe  was  thought  to  be  particularly 

1  Gardeners'  Chronicle,  1844,  Jan.  27,  53. 

a  "  Hist,  of  the  Mass.  Hort.  Soc.,"  1829-1878,  256.  Country  Gentleman,  1842, 
134. 

•  " London's  Encyclopaedia  of  Gardening,"  1878,  785. 


Early  History  of  Liquid  Applications.         15 

valuable  for  the  destruction  of  coccus,  or  scale  insects ;  it  was 
made  as  follows : 

Soft  soap 1  pound. 

Flowers  of  sulphur 1    " 

Tobacco I    " 

Nux  vomica 1  ounce. 

Soft  water 4  gallons. 

These  materials  were  well  mixed  with  the  water  and  then 
boiled  until  the  amount  of  liquor  was  reduced  to  three  gallons. 
It  was  then  allowed  to  cool,  and  was  ready  for  use.  Plants 
which  were  not  in  active  growth,  and  whose  foliage  was  not  too 
tender,  were  dipped  into  the  mixture.  For  overhead  syringing, 
the  liquid  was  diluted  one-third  with  water. 

Hamilton's  recipe  is  also  given:1 

Sulphur 8  ounces. 

Scotch  snuff 8      " 

Hellebore  powder 6      " 

Nux  vomica 6      " 

Soft  soap 6      " 

Cayenne  pepper 1  ounce. 

Tobacco  liquor 1  quart. 

Water  (boiling) 1  gallon. 

Stir  and  render  as  fine  as  possible,  and  then  strain  through  a 
rough  cloth.  Hamilton  did  not  appear  to  feel  very  confident  of 
the  action  of  even  this  array  of  death-dealing  matter,  so  he 
advised  in  addition  that  the  plants  be  washed  with  it,  and  the 
insects  removed  while  washing.  When  so  used  it  would  doubt- 
less act  as  a  specific.  The  recipe  is  also  interesting  from  the 
fact  that  it  contains  hellebore  as  one  of  the  ingredients;  for 
at  that  time  the  use  of  this  poison  was  probably  somewhat 
limited.  The  insecticidal  value  of  decoctions  made  of  the  wood 
of  quassia  was  also  known  to  a  limited  extent;  but  the  material 
has  been  more  widely  recommended  than  used. 

Hemery,  a  French  nurseryman,  made  a  compound  2  which  he 
said  would  destroy  mildew  on  peaches  if  only  one  application 
were  made.  It  contained  some  materials  which  unquestionably 

1  "  London's  Encyclopaedia  of  Gardening,"  1878,  785,  quoted  from  Speechly, 
"Treatise  on  the  Pine,"  1779,  60. 

*  Bevue  HorticoU,  1849,  Sept.  15,  360. 


16  The  Spraying  of  Plants. 

possessed  "  strength,"  but  whether  best  adapted  for  the  purpose 
designed  may  be  open  to  doubt : 

(a)  Aconite  branches  and  tubercles 1  kilogram. 

Water 4  liters. 

(6)  Pigeon  dung 25    " 

Urine 1  hectoliter. 

Mixture  (6)  was  allowed  to  ferment  forty-eight  hours,  and 
infusion  (a)  was  added  only  just  before  the  mixture  was  used. 
The  applications  should  be  made  in  April. 

The  most  important  and  probably  the  most  effective  form  in 
which  sulphur  was  used  was  the  solution  known  as  the  "  Grison 
liquid  "  (eau  Grison).  It  was  also  called  the  poly-  or  the  hydro- 
sulphur  of  Grison ;  it  is  still  in  use,  although  not  so  commonly 
as  heretofore.  Grison  was  head  gardener  of  the  vegetable 
houses  (serres  du  potager)  at  Versailles,  France,  and  in  1851 
he  first  made  the  solution.  He  used  * 

Flowers  of  sulphur , » .  .500  grams. 

Freshly  slaked  lime .,..500     " 

Water .........     3  liters. 

Boil  the  above  for  ten  minutes,  allow  the  mixture  to  settle, 
and  then  draw  off  the  clear  liquid.  Keep  this  in  bottles  and 
before  using  add  one  hundred  parts  of  water  to  one  part  of  the 
liquid.  Apply  with  a  syringe.  This  solution  is  excellent  for 
all  surface  mildews,  and  three  applications  are  sufficient  to  pro- 
tect foliage.  Later  the  quantity  of  sulphur  and  of  lime  was 
reduced  one-half  and  it  is  one  of  the  few  early  fungicidal  prepa- 
rations still  in  use.  An  Englishman  claims 2  to  have  used  a 
similar  preparation  as  early  as  1845,  using  one  part  of  sulphur, 
one  part  of  lime,  and  one  hundred  parts  of  water.  Grison, 
however,  appears  to  have  been  entirely  independent  in  the 
manufacture  of  his  preparation,  and  it  soon  became  much 
better  known  than  the  other. 

Lime  wash  was  recommended  in  America  against  curculio  of 
plums  in  1850.  Lawrence  Young,  of  Louisville,  Ky.,  seems  to 
have  been  one  of  the  first  to  try  this  remedy,  and  it  was  ap- 
parently successful.3  "  It  consists  simply  of  covering  the  young 

i  Revue  Horticole,  1852,  May  1,  168. 

*  Tuck,  Gard.  Chror   1852.  July  27,  419.      3  Country  Gentleman,  1850,  333. 


Early  History  of  Liquid  Applications.         17 

fruit,  as  soon  as  danger  is  apprehended,  with  a  coating  of  thin 
lime  wash,  considerably  more  dilute  than  the  mixture  em- 
ployed in  white-washing." 

The  use  of  quassia  chips  was  adopted  in  America  soon  after 
hellebore  became  known.  In  1855  the  material  was  recom- 
mended as  a  remedy  for  aphis,  being  prepared  by  boiling 

Quassia  chips 1  pound. 

Water 8  gallons. 

The  liquid  was  boiled  until  the  decoction  had  been  reduced 
to  six  gallons.1 

An  interesting  article  by  W.  F.  Radclyffe  appeared  in  one 
of  the  English  journals2  in  1861.  The  writer,  knowing  the 
value  of  copper  sulphate  when  used  upon  smutty  seed-wheat, 
reasoned  that  the  rose  mildew,  being  also  a  fungous  trouble, 
should  likewise  yield  to  treatment  by  this  chemical.  He  there- 
fore applied  a  solution  of  two  ounces  of  blue  vitriol  dissolved  in 
a  "  stable  bucket "  of  water  to  live  plants  by  means  of  a  fine 
spout,  and  entirely  freed  his  plants  from  the  disease.  The 
statement  was  also  made  that  weaker  solutions  would  be  tried 
the  following  year.  A  few  weeks  later  a  note  appeared  in  the 
same  journal  which  warned  growers  against  the  use  of  the  sul- 
phate of  copper,  as  it  would  kill  roses  if  it  came  in  contact  with 
their  roots.  No  further  mention  of  the  remedy  was  made,  and 
even  the  following  year  brought  no  account  of  any  experiments 
made  by  Radclyffe.  What  millions  might  have  been  saved 
had  this  important  work  been  carried  only  a  little  further ! 
But  the  old  remedies  continued  to  be  used  until  about  1870 ; 
insects  and  fungi  were  treated  practically  the  same  in  Europe 
and  in  America,  and  changes  of  only  minor  importance  were 
made. 

The  Americans  profited  very  largely  from  the  experience  of 
European  gardeners,  but  a  few  new  methods  of  treatment  also 
arose  in  this  country.  It  could  not  be  otherwise,  for  different 
enemies  had  to  be  dealt  with,  and  these  required  different  treat- 
ments. But  these  variations  were  comparatively  slight,  and 
the  remedies  used  in  the  first  half  of  the  century  were  more  or 
less  common  as  late  as  1880.  Sulphur  in  some  form  was  every- 

1  Michigan  Farmer.    Cited  in  Country  Gentleman,  1855,  April  12,  235. 
*  Gard.  Chron.  1861,  Nov.  2,  967. 
C 


18  The  Spraying  of  Plants. 

where  the  standard  remedy  for  mildews,  and  when  this  failed, 
growers  were  at  a  loss  to  apply  anything  more  efficient.  The 
best  insecticides  were  the  various  forms  of  soap,  tobacco,  quassia 
chips,  carbolic  acid,  and  hellebore,  although  the  last  was  a  com- 
paratively new  remedy.  Kerosene  was  also  used  in  America  to 
a  limited  extent.  With  these  materials  gardeners  and  fruit 
growers  managed,  as  a  rule,  to  produce  good  crops. 

But  a  change  was  to  come.  In  America  it  was  brought  about 
by  insects ;  these  became  so  abundant  and  began  to  do  so  much 
damage  in  districts  that  before  had  not  suffered  seriously,  that 
new  remedial  measures  were  demanded.  A  new  insect,  the 
potato  beetle,  was  introduced  from  the  far  West,  and  this  threat- 
ened to  be  even  more  destructive  than  those  which  were  in- 
digenous to  the  East. 

In  Europe  the  revolution  was  brought  about  by  fungi,  but 
not  by  the  European  types.  They  came  from  America,  and 
have  shown,  in  southern  Europe  particularly,  the  same  push 
and  energy  which  is  everywhere  recognized  as  characteristic  of 
the  American.  And  so  it  came  that  while  the  growers  in 
France  were  combatting  fungi,  those  in  America  were  contend- 
ing against  insects,  and  a  great  difference  soon  arose  in  the 
methods  of  treatment  adopted.  It  was  a  veritable  revolution ; 
for  old  remedies  were  obliged  to  give  way  to  new  ones,  and 
established  methods  to  those  but  little  tried.  Indeed,  the 
change  marks  an  epoch  in  the  history  of  the  cultivation  of 
plants. 


CHAPTER   II. 
SPRAYING  IN  FOREIGN  COUNTRIES. 

I.   IN  FRANCE. 
Discursive  Trials  of  Fungicides. 

No  important  changes  took  place  in  the  materials  used  by 
the  French  for  the  destruction  of  fungi  and  insects  until  about 
the  year  1882.  The  use  of  chemicals  in  place  of  the  substances 
which  appeal  strongly  to  the  senses  had  increased,  for  an  occa- 
sional mention  is  made  regarding  the  more  or  less  successful 
trial  of  some  new  material  of  this  character.  Gironard1  says 
that  in  1862  the  idea  occurred  to  him  to  use  from  two  to  four 
grams  of  acetate  of  potassium  in  one  liter  of  water  for  the  pre- 
vention of  mildew  on  grapes.  The  results  were  very  marked, 
and  in  1863  the  vines  were  productive  directly  in  proportion 
to  the  amounts  of  the  chemical  applied.  But  this  substance 
did  not  come  into  general  use,  and  it  was  not  until  the  value  of 
the  compounds  of  copper  became  known  that  any  permanent 
advances  were  made. 

Soon  after  the  appearance  in  France  of  the  downy  mildew 
(Peronospora  viticola)  the  necessity  for  a  more  energetic  fungi- 
cide than  sulphur  became  evident.  Sulphur  as  then  used  seemed 
to  be  entirely  without  effect  in  checking  the  progress  of  this 
disease.  The  mildew  was  first  discovered  in  France  in  1878. 2 
Millardet  saw  it  in  September  of  that  year  upon  some  American 
grape  seedlings  growing  in  the  nursery  of  the  Societe  d' Agricul- 
ture de  la  Gironde,  and  Plachon  at  the  same  time  recognized  it 

1  Bulletin  de  la  Societe  d' Horticulture  d '  Eure-et-Loirt  1863,  No.  13,  January, 
270. 

2  Jour.  d'Ag.  Prat.  1881,  Feb.  10, 192. 

19 


20  The  Spraying  of  Plants. 

on  the  leaves  of  Jacquez  grapes  at  Coutras  and  also  received  it 
from  various  departments  of  Lot-et-Garonne,  and  of  Rhone. 
The  disease  spread  rapidly  and  was  so  destructive  that  in  1882 
the  fruit  in  many  vineyards  was  almost  entirely  destroyed.  The 
climate  of  France  appears  to  be  peculiarly  adapted  to  the 
growth  of  this  mildew,  which  flourishes  as  well  upon  the  varie- 
ties of  Vitis  vinifera  as  upon  our  American  species.  In  moist 
seasons  it  is  fully  as  energetic  as  in  America,  or  even  more  so. 
The  leaves  fall  from  the  vines,  and  the  grapes  are  thus  prevented 
from  ripening  properly.  Even  in  cases  in  which  the  vines  do 
not  lose  all  their  foliage,  a  partial  reduction  is  sufficient  to  de- 
crease the  amount  of  sugar  in  the  grapes  to  such  an  extent  that 
their  value  for  wine  is  very  greatly  lessened.  Many  growers 
did  not  at  first  realize  the  seriousness  of  this  disease.  In  some 
vineyards  it  even  obtained  a  firm  foothold  without  being  noticed, 
for  the  portions  of  the  fungus  which  are  on  the  exterior  of  the 
leaves  are  borne  on  the  under  side.  When,  however,  it  became 
established  in  a  certain  district,  all  doubts  regarding  its  serious- 
ness vanished,  and  the  vineyardists  found  themselves  confronted 
by  a  disease  which  not  only  threatened  to  destroy  their  vines, 
but  which  gave  unmistakable  proof  of  its  power  to  do  so. 

The  remedies  in  general  use  for  controlling  the  European 
surface  mildew  (Oidium  Tuckeri)  proved  to  be  of  little  value 
against  this  new  foe.  Spraying  with  milk  of  lime  was  recom- 
mended and  very  thoroughly  tried,  but  it  did  not  give  such 
good  results  in  France  as  were  reported  from  Italy.  The  milk 
of  lime  was  used  with  good  results  against  the  oidium  of  the 
grape  by  Professor  Keller  even  before  1852.1  In  1881  Professor 
Garovaglio,  director  of  the  cryptogamic  laboratory  at  Pavie, 
used  it  with  fairly  good  success  against  the  peronospora,  but  his 
statement  of  this  work,  although  apparently  of  the  greatest  im- 
portance, received  no  attention  from  Italian  vineyardists.  It 
was  not  until  1883,  when  the  work  of  the  agricultural  school  at 
Conegliano,  Italy,  became  known,  that  the  remedy  was  generally 
adopted.  Many  growers  in  northern  Italy,  especially  the  Bel- 
lussi  Brothers,  near  Conegliano,  were  particularly  successful, 
and  so  much  confidence  was  placed  in  their  method  of  control- 
ling the  mildew  that  the  minister  of  agriculture,  in  a  circular 
published  in  1885  recommended  its  general  adoption.  During 

1  Cerlettie  Cuboni,  Annali  di  Agricoltura,  1886,  20. 


Spraying  in  Foreign  Countries.  21 

this  same  year  Cerletti  published l  an  important  article  in  which 
he  announced  that  the  peronospora  could  be  effectually  com- 
bated by  the  use  of  the  milk  of  lime.  The  mixture  was  made 
by  slaking  3  kilos  of  quicklime  in  100  liters  of  water,  first  con- 
verting the  lime  into  a  fine  powder,  by  partially  slaking  it,  and 
then  adding  the  remainder  of  the  water.2 

Powders  were  very  extensively  tried  in  France.  Their  use  was 
undoubtedly  suggested  by  the  fact  that  sulphur  had  been  applied 
in  the  form  of  a  powder  for  a  great  many  years.  There  was  at 
this  time  no  apparatus  particularly  adapted  to  the  application 
of  liquids,  but  such  was  not  the  case  with  powders.  As  early  as 
1881  3  Professor  Millardet,  of  the  Faculty  of  Sciences  of  Bor- 
deaux, used  the  sulphate  of  iron  in  powdered  form  in  connec- 
tion with  sulphur  and  also  with  plaster.  He  reported  to  Mme. 
Ponsot  (who  suggested  this  practice,  and  with  whom  he  carried 
on  the  work)  that  4  kilos4  of  sulphate  of  iron  mixed  with 
20  kilos  of  plaster  had  stopped  the  mildew. 

J.  Laure,5  an  engineer  at  Apt  (Vaucluse),  had  for  several 
years  made  a  study  of  a  certain  ore  of  sulphur,  called  "  Souf  res 
des  Tapets."  This  mineral  contained  various  substances  besides 
sulphur,  and  after  having  been  treated  so  that  it  contained  more 
or  less  of  the  sulphate  of  iron  it  was  sold  under  the  name  of 
"Fungivore."  It  was  highly  recommended  against  attacks. of 
anthracnose,  and  was  also  very  effective  in  checking  the  oidium 
of  the  vine.  From  three  to  six  applications  were  necessary  to 
protect  the  plant  well.  It  was  used  to  a  considerable  extent, 
but  this  powder,  as  well  as  the  many  others  which  were  sold,  did 
not  equal  the  liquid  applications  in  efficiency.  (See  page  32  for 
a  more  complete  discussion  of  the  powders  which  came  into  use 
as  fungicides.) 

Other  fungous  diseases  than  those  of  the  grape  were  now 
attracting  attention.  Paul  Oliver  said6  that  for  several  years 
pears  had  suffered  from  the  attacks  of  a  fungus  which  pro- 

1  Rirista  di  Viticoltura,  1885,  Ang.  30. 

2  Pinolini,  "  Le  Crittogame,"  1SSS,  30  et  seq. 

3  Jour.  &Ag.  Prat.  1SS3,  April  19,  553. 

4  One  kilogram  is  equal  to  2.2  pounds.     Since  the  metric  system  is  the  one 
used  by  the  large  majority  of  the  experimenters  of  continental  Europe,  the  system 
will  be  retained  in  this  portion  of  the  work.     For  a  complete  scheme  of  the  weights 
and  measures  of  the  metric  system,  as  well  as  their  equivalents,  see  Appendix. 

c  Jour.  d'Ag.  Prat.  1883," April  19,  554.  o  /j^.  issi,  July  7,  20. 


22  The  Spraying  of  Plants. 

duced  black,  velvety  spots  upon  the  foliage,  and  in  1880  it  also 
deformed  the  fruit  to  a  considerable  extent.  The  cause  of 
the  injury  was  attributed  by  Prillieux,1  the  inspector-general 
of  Agricultural  Education,  to  Fusicladium  pyrinum  (  Cladosporium 
dendriticum,  Walr.),  and  a  description  of  the  fungus  was  pub- 
lished. Paul  Oliver  2  made  some  experiments  which  were  de- 
signed to  throw  light  upon  the  best  method  of  destroying  the 
spores  of  the  parasite.  The  materials  used  were,  (1)  pure  water ; 
(2)  water  acidulated  with  one-twentieth  its  amount  of  sulphuric 
acid ;  (3)  a  33|  per  cent  solution  of  the  sulphate  of  iron ;  (4)  a 
16f  per  cent  solution  of  the  sulphate  of  copper.  He  advised  the 
use  of  the  last  in  rainy  weather,  but  during  dry  weather  either 
the  second  or  the  third  would  prove  effective.  Oliver  further 
states  that  he  succeeded  in  killing  the  spores  of  F.  pyrinum  with 
an  8  per  cent  solution  8  of  copper  sulphate,  and  that  he  sprayed 
his  trees  with  a  10  per  cent  solution  during  the  winter  of  1882-3. 

This  discovery — that  the  salts  of  copper  would  prevent  the 
germination  of  the  spores  of  fungi  —  was  by  no  means  new.  As 
early  as  1807,  Benedict  Prevost  gave  4  an  account  of  the  method 
by  which  he  prevented  the  germination  of  the  spores  of  a  fun- 
gous disease  commonly  known  as  "  Carie,"  or  "  Charbon " 
(smut),  of  corn.  His  statement  regarding  the  result  of  his 
experiments  is  as  follows  :  "  The  amount  of  sulphate  of  copper 
really  necessary  to  give  to  water  the  power  of  preventing  the 
germination  of  the  spores  in  a  low  temperature  does  not 
amount  to  ^oW  of  its  weight,  and  TT^™  retards  germina- 
tion." Thus  a  discovery  of  immense  practical  importance  has 
long  remained  hidden  and  unappreciated,  and  it  is  not  impos- 
sible that  other  information  equally  valuable  is  at  present 
neglected  in  a  similar  manner. 

The  first  general  statement  in  regard  to  the  value  of  chemi- 
cal compounds  for  the  destruction  of  grape  mildew  seems  to 
have  been  made  by  Millardet.5  He  says :  "  Recent  observa- 

1  Comptes  Rendus  de  VAcademie  des  Sciences,  1877,  Nov.  12. 

*  Jour.  d'Ag.  Prat.  1881,  July  7,  20. 

8  By  an  8  per  cent  solution  is  meant  a  solution  which  contains  8  parts  by 
weight  of  the  solid  dissolved  in  100  parts  of  the  liquid. 

4  "  Memoire  sur  la  cause  immediate  de  la  Carie  ou  Charbon  des  bles."  Montau- 
ban,  1807. 

6  Zeitechrift  in  Wein-,  Obnt-,  und  Garteribau  fur  Elsass-Lothringen,  18S3, 
March  1  and  15. 


Introduction  of  Copper  Salts.  23 

tions  make  me  hope  that  perhaps  the  most  satisfactory  results 
may  be  obtained  by  the  use  of  certain  mineral  solutions,  such  as, 
for  example,  the  sulphate  of  iron  or  of  copper."  But  no  definite 
experiment  had  been  made  up  to  this  date  to  prove  his  assertion. 

Prillieux  x  carried  on  experiments  at  Nerac  for  the  destruc- 
tion of  the  American  grape  mildew.  He  found  lime  to  be  of 
little  value.  Borate  of  soda,  used  at  the  rate  of  five  grams2 
dissolved  in  a  liter  3  of  water,  gave  good  results,  but  the  various 
toxics  and  antiseptics  used  by  him  were  practically  useless. 

A  concentrated  solution  of  the  sulphate  of  iron  for  the  de- 
struction of  anthracnose  was  already  regarded  as  a  specific,4 
for  it  had  long  been  used  with  success  in  the  treatment  of 
the  disease.  The  practice  appears  to  have  originated  with 
Schnorf,  of  Rossbach-Meilen,  Germany,  for  he  writes  as  follows 
regarding  its  early  history : 5  "  During  twenty  years,  I  have 
successfully  used  the  sulphate  of  iron  for  anthracnose  of  the 
grape,  in  accordance  with  the  following  plan :  During  spring, 
before  the  vines  start,  I  dissolve  3  kilos  of  sulphate  of  iron 
in  6  liters  of  boiling  water.  When  the  solution  has  cooled, 
I  pour  it  into  earthen  vessels.  The  workmen  take  these  into 
the  vineyard  and  wash  the  vines  with  rags,  which  are  dipped 
into  the  liquid.  This  is  done  but  once  during  the  year,  in 
early  spring,  and  the  results  are  uniformly  excellent.  It  has 
occurred  that  during  certain  seasons  before  the  treatments 
were  begun,  I  lost  the  entire  crop  if  the  weather  was  cold  and 
moist,  while  I  have  rarely  failed  to  obtain  a  good  yield  since 
the  applications  were  made,  and  I  feel  well  repaid  for  my 
trouble.  I  repeat  the  washing  every  year,  and  other  vine- 
yardists  have  followed  my  example  with  equal  success." 

In  France  it  became  the  common  practice  to  cover  the  posts 
and  vines  with  this  solution  during  winter  or  early  spring,  a 
broom  or  brush  being  used  for  the  purpose.  In  some  cases  the 
entire  post  was  soaked  in  the  solution  for  several  days. 

P.  de  Lafitte  states  6  that  Sept.  20,  1884,   Ricaud  and  also 

i  Jour.  d'Aff.  Prat.  1882,  Jan.  19,  75. 
s  A  gram  is  equal  to  15.482  grains.    See  Appendix. 
8  A  liter  is  equal  to  1.056  quarts. 
«  Jour.  d'Ag.  Prat.  1883,  April  19,  553. 

6  Schweizer  Monats-Schrift  fur    Ob*t-  und  Weinbau,  1878,  ix.  155.    See  also 
La  Vigne  Americaine,  1879,  May,  No.  5. 
«  Jour.  d'Ag.  Prat.  1885,  Oct.  1,  479. 


24  The  Spraying  of  Plants. 

Paulin  published  in  the  Journal  de  Beaune  a  note  on  the 
good  effects  which  followed  the  covering  of  posts  with  a  con- 
centrated solution  of  the  sulphate  of  copper.  The  work  had 
been  done  in  Burgundy.  On  the  23d  of  September  the  above 
journal  also  contained  an  article  on  the  same  subject,  written 
by  Montoy.  Ad.  Perrey  mentions l  a  case  in  which  the  posts 
that  supported  the  vines  were  treated  with  a  solution  of  sul- 
phate of  copper,  and  this  caused  all  the  leaves  within  a  circle 
20-25  cm.  in  diameter,  the  post  being  at  the  center,  to  remain 
upon  the  vine.  Untreated  vines  lost  all  their  foliage.  Several 
other  observers  in  various  sections  of  France  noted  the  same 
fact,  and  all  agreed  that  the  beneficial  action  extended  to 
practically  the  same  distance  as  mentioned  above.2  The  prac- 
tice was  consequently  of  value  only  for  vines  not  more  than 
five  or  six  years  old,  since  larger  vines  carry  so  much  foliage 
outside  of  the  protected  belt.  Nevertheless,  many  growers  soon 
made  a  practice  of  covering  the  posts,  vines,  and  also  the 
tying  material,  with  a  strong  solution  of  copper  sulphate;  and 
some  believed  excellent  protection  followed  the  treatment.  But 
the  method  did  not  give  uniformly  good  results,  and  some 
more  effective  remedy  was  still  sought. 

In  1885  the  French  vineyardists  were  still  apparently  with- 
out a  good  remedy  for  the  mildew.  P.  Pichard,  director  of 
the  agricultural  station  at  Vaucluse,  proposed  3  a  solution  of 
the  liver  of  sulphur ;  and  Foe'x,  director  of  the  school  of  Viti- 
culture at  Montpellier,  asserted  4  that,  after  making  an  appli- 
cation of  an  emulsion  of  one  part  phenic  acid  in  100  parts 
of  soap  water,  all  traces  of  mildew  disappeared.  He  found  it 
advisable  to  add  glycerine  to  this  preparation,  in  order  to  pre- 
vent it  from  drying  too  fast.  V.  Cambon  advised  the  use  of 
a  2  per  cent  solution  of  bisulphate  of  soda. 

Origin  of  the  Bordeaux  Mixture. 

Such,  in  general,  was  the  nature  of  the  experimental  work 
which  was  done  at  this  time.  New  chemicals  were  tried,  as  well 

1  Jour.  d'Aff.  Prat.  1884,  Oct.  16,  540.     See  also  report  of  Van  Tieghem  to 
Academy  of  Sciences,  1884,  Sept.  29. 

2  Bidault,  Jour,  de  VAg.  1885,  Oct.  81,  712. 

3  Jour.  d'Ag.  Prat.  1885,  Feb.  5,  217. 
«  Jbid.  loo.  Git. 


Origin  of  the  Bordeaux  Mixture.  25 

as  many  different  combinations  of  old  ones.  Some  of  these 
proved  to  be  fairly  efficient,  but  the  ideal  remedy  had  by  no  means 
been  discovered.  It  was  not  until  the  fall  of  1885  that  there  ap- 
peared unmistakable  evidence,  based  upon  experiments,  that  a 
substance  had  been  found  which  promised  to  be  a  specific  against 
the  grape  mildew,  and  perhaps  also  against  many  other  fungous 
diseases.  This  substance  was  copper.  Its  history  is  all  the 
more  interesting  from  the  fact  that  the  first  use  of  its  most 
effective  combination  was  not  in  any  way  connected  with  the 
fungous  diseases  of  the  grape,  but  rather  with  the  human 
enemies  of  the  vineyardist.  Nevertheless,  when  the  mildew- 
appeared,  this  preparation  rose  to  the  occasion,  and  protected 
the  foliage,  as  well  as  it  had  done  the  fruit  of  the  vines. 

In  southwestern  France,  in  the  maritime  department  of 
Gironde,  is  situated  the  city  of  Bordeaux.  It  lies  near  the  west- 
ern border  of  a  large  horticultural  district  of  wrhich  the  grape 
is  by  far  the  most  important  fruit.  These  grapes  are  mostly 
manufactured  into  wine,  and  it  is  particularly  the  clarets  which 
have  made  this  district  known  throughout  the  world.  It  is 
here  that  the  downy  mildew  of  America  first  made  its  appear- 
ance in  Europe,  probably  in  1878,  and  here  also  it  first  became 
most  serious.  The  summer  of  1882  was  particularly  favorable 
to  its  development;  and  as  no  steps  had  been  taken  to  check 
its  progress,  the  injury  done  to  vineyards  was  very  great.  The 
foliage  of  the  vines  was  destroyed,  and  fell  to  the  ground  during 
the  summer.  This  prevented  the  proper  ripening  of  the  grapes, 
and  the  harvest  was  almost  without  value. 

A  few  vines,  however,  escape  this  general  attack.  These 
were  situated  along  the  highways,  particularly  about  Margaux, 
St.  Julian,  and  Pauillac,  in  the  Medoc.  It  was  noticed  by  many 
that  in  the  fall  of  1882  certain  vines  retained  their  foliage  in  an 
almost  perfect  condition.  Yineyardists  in  these  localities  had 
suffered  considerable  losses  from  the  stealing  of  their  grapes 
by  children  and  travelers  along  the  highways.  It  had  for- 
merly been  the  custom1  to  sprinkle  verdigris  upon  a  few  rows 
of  the  vines  nearest  to  the  road  for  the  purpose  of  giving  the 
fruit  the  appearance  of  having  been  poisoned.  Several  years 
before  the  appearance  of  the  downy  mildew  this  substance  was 

1  Millardet,  Jour.  d'Ag.  Prat.  1885,  Oct.  8,  514.  Prillieux,  "Report  to  the 
Minister  of  Agriculture,"  Oct.  22,  1885. 


26  The  Spraying  of  Plants. 

replaced,  from  reasons  of  economy,  by  a  mixture  of  the  milk 
of  lime  and  some  salt  of  copper,  the  sulphate  being  commonly 
used,  on  account  of  its  cheapness.  This  mixture  was  of  the 
consistency  of  cream,  and  was  of  a  light  blue  color.  It  was 
applied  to  the  vines  by  means  of  brooms,  or  whisks  of  heath. 
The  design  was  to  apply  enough  of  the  mixture  to  each  vine 
to  give  it  the  appearance  of  having  been  well  poisoned,  the 
operation,  of  course,  being  delayed  until  the  period  of  ripening 
approached. 

The  vines  thus  treated  were  the  ones  which  had  retained 
their  foliage  through  the  fall  of  1882,  while  others  growing 
further  from  the  road  lost  their  leaves.  The  cause  of  the 
beneficial  action  of  the  mixture  was  soon  ascribed  to  the 
copper,  for  lime  used  alone  had  proved  unsatisfactory  as  a 
remedy  for  mildew.  Prillieux  and  Millardet  were  among  the 
first  to  note  the  effect  of  the  mixture  and  to  ascribe  its  action 
to  the  proper  cause  ;  but  Millardet  is  the  one  who  did  the  most 
towards  perfecting  the  mixture  and  testing  its  action  upon 
foliage,  and  upon  the  mildew.  (See  frontispiece.)  He  was 
materially  assisted  by  U.  Gayon,  professor  of  chemistry  in  the 
Faculty  of  Sciences,  of  Bordeaux.  These  two  may  justly  be 
considered  the  leaders  in  the  study  and  use  of  the  preparation 
which  was  destined  to  prove  superior  to  all  fungicides  that 
have  been  used  to  the  present  day,  and  which  is  now  so  well 
known,  in  a  modified  form,  under  the  name  of  the  Bordeaux 
mixture . 

Although  these  men  were  the  most  energetic  in  conducting 
the  work,  and  the  first  to  publish  results,  they  apparently  were 
not  the  only  ones  working  in  this  field.  Prillieux  asserted  1 
that  the  treatments  of  Jouet  and  of  E.  Ferrand  were  made 
simultaneously  with  those  of  Millardet,  and  independently  of  the 
latter,  and  that  they  did  not  even  know  of  Millardet's  investiga- 
tions. Their  work,  however,  does  not  appear  to  have  been 
carried  on  systematically,  nor  were  results  published  which  go 
to  show  that  the  experiments  began  so  early  as  did  those  of 
Millardet  and  Gayon.  It  is  consequently  to  these  two  men  that 
the  honor  of  having  first  experimented  with  the  "bouillie 
bordelaise,"  as  it  then  began  to  be  called,  may  be  granted,  and 
to  Millardet  in  particular  may  be  given  the  credit  of  being  the 

1 8ociet4  Rationale  d' Agriculture  de  France,  session  of  Nov.  4,  1885,  590. 


Trials  of  Copper   Compounds.  27 

first  to  plan  and  publish  results  which  showed  plainly  the  value 
of  the  copper  compounds  in  commercial  work.1 

The  first  systematic  applications  of  copper  compounds  for  the 
prevention  of  the  downy  mildew  were  made 2  on  the  18th  of 
August,  1883,  or  the  year  following  the  observation  of  the  ap- 
parent value  of  lime  and  copper  sulphate  when  applied  together. 
The  work  was  done  on  the  grounds  of  the  castle  of  Danzac  in 
the  Medoc,  by  E.  David,  steward  of  the  place,  but  under  the 
direction  of  Millardet.  In  these  experiments  the  sulphates  of 
iron  and  of  copper  were  used.  They  were  applied  in  pure 
solutions,  and  also  mixed  with  lime  in  varying  proportions. 

In  1883  Millardet,  believing  that  copper  was  the  most  effi- 
cient agent  in  the  destruction  of  the  mildew,  applied  this  metal 
in  other  forms  than  the  sulphate.  He  used.3  in  addition,  the 
carbonate,  phosphate,  and  sulphide  of  copper,  and  also  the 
corresponding  salts  of  iron.  Lime  was  also  applied  alone.  In 
1884  the  same  wTork  was  repeated,  and  although  the  mildew  was 
not  very  abundant,  still  he  and  Mr.  David  came  to  the  conclu- 
sion that  the  mixture  of  the  sulphate  of  copper  and  the  milk  of 
lime  was  the  most  promising  of  all  the  materials  applied.  They 
decided  to  give  up  the  use  of  the  iron  salts,  as  well  as  the  sim- 
ple solution  of  copper  sulphate.  It  was  found  that  the  latter 
burned  the  leaves  when  used  stronger  than  one-half  part  of  the 
salt  in  100  parts  of  water.  This  result,  however,  does  not  agree 
with  those  obtained  by  Messrs.  Ad.  Perrey,  P.  de  Lafitte,  and 
Maginen.  On  the  estate  of  Salle  de  Pez,  at  St.  Estephe,  an 
8  per  cent  solution  of  copper  sulphate  proved  4  to  be  nearly  as 
efficient  as  when  lime  was  added. 

During  these  two  years  the  mildew  was  not  very  prevalent  in 
the  treated  vineyards,  so  that  only  partially  satisfactory  results 
were  obtained.  These  were,  however,  of  sufficient  value  to 
warrant  the  publication  5  of  an  article  by  Millardet,  in  which 
were  given  the  following  directions  for  preparing  and  applying 
the  mixture : 

"  In   100  liters  of    water    dissolve   8  kilos  of    commercial 

1  Jour.  d'Aff.  et  d'Hort.  de  la  Gironde,  Oct.  1.  Cited  in  Jour.  d?Ag.  Prat. 
1885,  Dec.  3,  804. 

*  Jour.  dJAg.  Prat.  1885,  Dec.  3,  804. 
» Ibid.  708. 

*  Ibid.  Nov.  5,  661,  662. 

«  Annales  de  la  Societe  d'Ag.  de  la  Gironde,  1885,  April  1,  73  et  eeq. 


28  The  Spraying  of  Plants. 

sulphate  of  copper.  In  another  vessel  make  a  milk  of  lime  by 
slaking  15  kilos  of  quicklime  in  30  liters  of  water.  This  is 
then  added  to  the  copper  sulphate  solution,  causing  a  bluish 
precipitate.  The  workman  should  stir  the  mixture  well,  and 
then  pour  a  part  of  it  into  a  pail  or  watering  pot.  This  is 
carried  in  the  left  hand  while  with  the  right  he  sprinkles  the 
foliage  by  means  of  a  small  broom.  Care  should  be  taken 
that  none  of  the  mixture  shall  strike  the  grapes."  Such  was 
the  first  formula  for  making  the  Bordeaux  mixture ;  and  the 
first  apparatus  used  for  its  application  was  a  broom  ! 

On  Dec.  3,  1884,  some  time  previous  to  this  publication, 
Baron  Chatry  de  la  Fosse  had  called  the  attention  of  the  Agri- 
cultural Society  of  Gironde  to  the  good  effects  following  the 
use  of  the  mixture  of  lime  and  copper  sulphate,  but  he  gave  no 
direction  for  its  preparation  nor  for  its  use. 

During  1885  the  downy  mildew  developed  with  much  inten- 
sity. Many  experiments  were  tried,  and  the  year  brought  out  a 
number  of  facts  regarding  the  various  treatments.  The  value 
of  the  "  bouillie  bordelaise  "  was  proved  beyond  all  doubt. 
Wherever  it  had  been  properly  used,  the  results  were  all 
that  could  be  wished.  Untreated  vines  lost  their  leaves,  and 
those  to  which  the  mixture  had  been  applied,  retained  them 
in  an  almost  perfect  condition.  These  results  are  all  the  more 
remarkable  on  account  of  the  very  crude  method  of  applying 
the  mixture,  a  small  broom  being  generally  used  for  the  pur- 
pose. The  most  marked  and  promising  results  of  the  year 
were  probably  obtained  by  de  Ferrand,  Johnston,  and  David.1 

The  original  formula  of  the  mixture  was  modified  by  various 
vineyardists  in  1885.  De  Ferrand  used 2  successfully  about 
the  same  quantity  of  lime  as  of  copper  sulphate.  David  added3 
glue  to  the  mixture  at  the  rate  of  6  kilos  strong  glue  dissolved 
in  800  liters  of  the  mixture.  This  first  trial  of  the  addition  of 
glue  was  apparently  followed  by  beneficial  results. 

The  first  application  of  the  Bordeaux  mixture  for  the  pre- 
vention of  other  diseases  than  those  of  the  vine  seems  also  to 
have  been  made  this  year.  Prillieux,  in  his  report  to  the 
minister  of  agriculture,  dated  Oct.  22,  1885,  says  4  that  Jouet, 
at  Chateau-Langoa  (Medoc),  made  an  application  to  tomatoes 

1  Jour.  d'Ag.  Prat.  1885,  699  et  seq.  9  Ibid.  661. 

2  Ibid.  701.  *  Ibid.  662. 


The  Fungicides  of  1885.  29 

which  were  apparently  attacked  by  the  same  peronospora  that 
is  found  upon  potatoes.  He  believed  he  had  cured  or  stopped 
the  disease.  Since  this  fungus  is  closely  related  to  the  peronos- 
pora of  the  vine,  it  seemed  very  probable  that  the  remedy  would 
prove  equally  valuable  for  all  similar  diseases.  Prillieux  even 
went  so  far  as  to  advise,  for  the  first  time,  the  use  of  the  mix- 
ture upon  potatoes  and  tomatoes,  and  events  have  shown  that 
his  advice  was  well  worthy  of  being  followed. 

At  the  beginning  of  the  year  1885  the  general  opinion  ap- 
pears to  have  been  to  wait  until  the  appearance  of  the  mildew 
upon  the  vines  before  making  an  application ;  and  it  was  also 
believed  that  one  treatment  was  sufficient.  But  after  the  work 
of  the  year  Millardet  thought 1  that  in  case  of  severe  rains  it 
might  be  advisable  to  make  a  second. 

At  the  close  of  the  year  Prosper  de  Lafitte  summed  2  up  the 
methods  then  in  use  for  checking  the  downy  mildew  of  the 
grape,  as  follows : 

1.  "  The  treatment  of  Beaune,  which  consists  in  covering  the 
posts  and  the  tying  material,  rye  straw  being  commonly  used 
for  this  purpose,  with  a  five-tenths  per  cent  solution  of  copper 
sulphate.     (Page  24.) 

2.  "  The  treatment  of  which  Millardet  is  the  promoter  "  con- 
sists in  protecting  the  vines  by  means  of  a  mixture  of  the  milk 
of  lime  and  a  solution  of  copper  sulphate.     (Page  27.) 

3.  "  Spraying  the  foliage  with  a  simple  solution  of  copper 
sulphate.     (Page  27.) 

4.  "  Spraying  the  foliage  with  the  milk  of  lime,  using  approx- 
imately a  2  per  cent  mixture."     (Page  20.) 

To  the  above  might  have  been  added  also : 

5.  The  treatment  which  consists  in  the  application  of  pow- 
ders.    (Page  32.) 

The  use  of  the  "  bouillie  bordelaise  "  became  more  general  in 
1886  and  many  cases  are  reported  in  which  its  beneficial  and 
almost  specific  action  was  proved.  The  general  opinion  seemed 
to  be  that  it  was  superior  to  any  of  the  other  substances  recom- 
mended. 

In  accordance  with  the  advice  given  by  Prillieux  in  the  fall 
of  1885  Jouet,  in  the  Medoc,  made  what  appears  to  have  been 
the  first  application  of  the  mixture  to  potatoes  for  the  preven- 

i  Jour.  &Ag.  Prat.  1886,  734.  2  Ibid.  880  et  seq. 


30  The  Spraying  of  Plants. 

tion  of  the  rot,  a  disease  which  was  then  very  destructive.  The 
experiment  is  reported  *  by  Prillieux,  who  says  that  the  area 
treated  covered  about  three  hectares.2  The  application  was 
made  as  soon  as  the  rot  appeared,  and  no  further  injury  resulted 
from  the  disease.  Jouet  was  equally  successful  with  the  blight 
of  tomatoes,  both  diseases  being  attributed  to  Phytophthora  in- 
festans,  DeBary.  Another  tomato  grower,  at  Scully,  is  likewise 
reported  to  have  been  successful. 

Origin  of  the  Ammoniated  Copper  Fungicides,  and 
Various  Combinations. 

A  new  fungicide,  one  destined  to  become  very  well  known, 
was  tried  in  1885  for  the  first  time.  It  was  proposed 3  by 
Professor  Audoynaud  of  the  agricultural  school  at  Montpellier. 
He  gave  the  following  directions  for  its  preparation : 

Copper  sulphate 1  kilo. 

Ammonia 1  liter. 

Water,  sufficient  to  spray 1  hectare. 

The  copper  salt  was  dissolved  in  the  ammonia  and  then  this 
solution  was  added  to  the  water.  Such  a  solution  had  already 
been  known  to  pharmacists  under  the  name  of  "eau  celeste," 
meaning  "  heavenly  water,"  so  called  on  account  of  its  deep 
blue  color.  It  was  used  during  the  year  by  several  experi- 
menters. 

In  1886  a  great  many  men  conducted  experiments  to  test  the 
value  of  the  compounds  of  copper,  very  few  other  substances 
being  used.  Among  the  many  who  did  valuable  work  during 
the  year  may  be  named  Millardet  and  David,4  Gaillot,  and 
Dr.  G.  Patrigeon.5  These  experimenters  planned  the  work  so 
thoroughly  that  their  results  embodied  the  most  important  of 
those  obtained  by  other  workers. 

In  almost  every  instance  the  "  bouillie  bordelaise,"  or  Bor- 
deaux mixture,  gave  the  most  satisfactory  results.  Millardet 

1  Socttte  Nat.  d'Ag.  de  France,  session  of  Aug.  18,  1886,  465. 
8  A  hectare  is  2.47  acres. 

»  Progres  Agricole  et  Viticole,  1886,  March  28.  Cited  by  Viala  et  Ferrouillat, 
"Traitment  des  Maladies  de  la  Vigne,"  1888,  30. 

*  Jour.  d'Ag.  Prat.  1886,  Nov.  25,  764 ;  Dec.  9,  831. 
« Ibid.  Nov.  11,  696. 


Liquid  Fungicides  of  1886.  31 

found  that  the  mixture  could  also  be  made  with  air-slaked 
lime,  but  it  then  had  the  disadvantage  of  being  more  difficult 
to  apply.  He  came  to  the  conclusion  that  the  addition  of  glue 
was  of  no  particular  value.  Eau  celeste  proved  to  be  a  very 
adhesive  solution,  and  it  also  showed  very  efficient  f  imgicidal 
propeH^.cf: ,  out  it  burned  the  foliage  considerably  and  on  that 
account  was  open  to  objection.  Simple  solutions  of  the  sul- 
phate of  copper,  of  varying  strength,  were  applied,  but  although 
the  weakest  contained  only  one-half  per  cent  of  the  salt,  the 
foliage  was  in  every  case  burned. 

L.  Gaillot,  of  Beaune  (Cote  d'Or),  had  difficulty  in  obtaining 
apparatus  for  throwing  the  Bordeaux  mixture  when  made 
according  to  the  original  formula,  and  so  searched  for  some 
simpler  preparation.1  It  *  ras  at  that  time  a  common  belief  in 
Burgundy  that  the  first  treatments  need  not  be  strong,  for  even 
treating  the  posts  was  of  benefit.  After  many  trials,  Gaillot 
was  led,  in  1886,  to  make  use  of  formulas  which  called  for  only 
one  or  two  kilos  of  copper  sulphate,  and  only  one  kilo  of  lime, 
these  being  applied  in  one  hectoliter  of  water. 

Gaillot  appears  also  to  have  been  the  first  to  make  a  success- 
ful preparation  of  sulphur  and  the  Bordeaux  mixture.2  He 
used  the  following  formula : 

Copper  sulphate 1  kilo. 

Water 100  liters. 

In  another  vessel  he  placed 

Quicklime 5  kilos. 

Water 5-6  liters. 

When  this  was  thoroughly  slaked,  he  added 

Flowers  of  sulphur 1  kilo. 

This  was  thoroughly  mixed  with  the  lime  paste,  and  to  the 
mixture  he  added  small  quantities  of  the  copper  sulphate  solu- 
tion, stirring  well.  When  the  number  of  additions  caused  the 
material  to  be  of  a  semi-fluid  consistency,  it  was  poured  into 
the  barrel  containing  the  copper  sulphate  solution.  The  con- 

1  Jour.  d'Aff.  Prat.  1888,  May  24,  782.    See  also  "Compte  Eendu  du  Congres 
de  Dijon,"  1886;   Vigne  frangaise,  1886,  Sept.  15,  276,  over  initials  B.  J. 
*  "Compte  Eendu  des  Reunions  Viticoles,"  Dijon,  1886,  June  4  and  5,  65. 


32  The  Spraying  of  Plants. 

tents  of  the  barrel  were  well  stirred  before  any  of  the  mixture 
was  removed. 

"  Bouillies  bourguignonnes  "  is  the  name  which  Galliot  pro- 
posed, in  1888,1  for  the  designation  of  the  Bordeaux  mixture 
which  contained  only  one  or  two  kilos  of  copper  sulphate.  The 
name  never  came  into  common  use,  for  the  term  "bouillie  bor- 
delaise  "  was  so  well  known  that  it  could  not  be  easily  sup- 
planted, however  just  the  cause  for  dropping  it  may  have  been. 
Millardet  recommended  a  similar  formula  in  1887,  as  a  modifi- 
cation of  the  original. 

Gaillot  says  that  in  1886  he  protected  his  grapes  perfectly  by 
the  use  of  the  mixture  of  sulphur  and  the  bouillie  bourgui- 
gnonne.  He  made  the  first  application  in  April,  using  a  mixture 
containing  two  kilos  copper  sulphate ;  about  eight  days  after 
flowering  he  applied  the  weaker  mixture  having  only  one  kilo 
of  the  sulphate.  The  third  treatment  was  made  late  in  the  sea- 
son, and  the  vines  were  injured  neither  by  fungi  nor  by  the 
materials. 

Powders. 

During  1886  Millardet  experimented  extensively  with  pow- 
ders. He  used  them  upon  the  vines  in  the  hope  that  they 
would  prove  as  valuable  as  the  liquids  then  in  use.  Apparatus 
for  applying  powders  had  already  been  manufactured  and  it 
was  very  desirable  that  an  efficient  preparation  might  be 
found.  The  one  that  appeared  to  be  the  most  promising  was 
the  Podechard  powder.2  It  was  made  by  Louis  Podechard,  of 
Gigny,  according  to  the  following  formula : 

Quicklime 100  kilos. 

Sulphate  of  copper 20    " 

Flowers  of  sulphur 10    " 

Wood  ashes 15    " 

Water  at  20°  C 50  liters. 

The  sulphur  should  be  added  after  the  other  ingredients 
have  been  allowed  to  stand  twenty-four  hours.  Then  mix  all 
together,  dry  the  mass,  and  force  it  through  a  fine  sieve. 

1  Jour.  d'Ag.  Prat.  1888,  May  24,  733. 

*Ibid.  1887,  May  5,  642.  See  also  bulletin  du  comite  d' Agriculture  de 

V  Arrondissement  de  £eaune,  October,  1885,  4-10 ;  Jowr.  d'Ag.  Prat.  1885, 
Dec.  3,  808. 


Powders  in  1886.  83 

This  powder  in  a  certain  sense  forms  a  link  between  the  older 
ones  in  which  the  ingredients  "  ought "  to  be  of  value,  and  the 
later  ones  in  which  every  material  was  known  to  possess  a  defi- 
nite composition  and  also  a  more  or  less  definite  action  as  a 
fungicide. 

The  David  powder  was  used  for  the  first  time  in  these  exper- 
iments. It  was  named  in  honor  of  Mr.  David,  who  rendered 
such  material  assistance  to  Millardet.  The  powder  was  com- 
posed of 

Quicklime 30  kilos. 

Copper  sulphate 8    " 

As  small  a  quantity  of  water  as  possible  was  used  to  slake 
the  lime,  and  to  dissolve  the  sulphate.  The  latter  solution  was 
added  to  the  milk  of  lime  when  it  had  cooled,  and  then  the  mix- 
ture was  dried  in  the  sun.  When  perfectly  dry  it  was  ground 
into  very  fine  powder  which  was  of  a  blue  color. 

Sulphosteatite  was  also  used  in  these  experiments.  This  sub- 
stance was  often  called  "  steatite  cuprique,"  and  to  many  Ameri- 
can readers  it  may  be  still  more  familiar  under  the  name  of 
"  fostite,"  a  term  first  used  in  1894.  This  substance  was  pro- 
posed by  Baron  Chefdebien,  of  Perpignan. 

Millardet  used  a  powder  known  as  "  sulfatme,"  made  by 
Paul  Esteve,  of  Montpellier.  It  was  composed  mainly  of  sul- 
phur, lime,  sulphate  of  copper,  and  plaster,  and  was  first  made 
generally  known  in  Progres  Agricole  et  Viticole,  Nov.  14,  1884. 

Sulfatine  gave  the  best  results  of  any  of  the  powders  as 
regards  fungicidai  action.  Sulphosteatite  proved  to  be  the 
most  adhesive,  but  it  burned  the  foliage  of  the  vines,  and  for 
that  reason  it  required  careful  distribution.  This  powder  had 
previously  been  mentioned  as  possessing  no  value  against  the 
oidium,  and  the  Bordeaux  mixture  was  spoken  of  in  a  similar 
manner. l  David's  powder  was  not  so  active  against  the  mildew 
as  was  the  Bordeaux  mixture,  and  in  addition  it  cost  about 
four  times  as  much.  More  material  was  required  to  cover  a 
given  area,  and  its  use  was  not  advised  from  a  commercial 
standpoint.  Podechard's  powder  proved  to  be  practically  worth- 
less, and  other  growers  who  used  it  came  to  the  same  conclu- 
sion. 

i  Jvur.  d'Ag.  Prat.  1886,  Nov.  4,  663. 
D 


34  The  Spraying  of  Plants. 

Perfection  of  the  Fungicides,  and  further  Experiments  in 
their  Use. 

Dr.  Patrigeon  tested  the  various  methods  of  applying  the 
copper  sulphate  solutions.  In  1886  he  treated,  in  different 
plots,  the  posts,  the  tying  material,  the  plants  themselves  during 
the  winter,  and  the  foliage.  He  also  added  10  per  cent  of 
plaster  to  a  1  per  cent  solution  of  copper  sulphate  and  applied 
this  mixture  with  a  broom.  This  last  preparation  possessed 
some  merit,  as  did  also  the  application  of  the  pure  sulphate  of 
copper  solution.  But  the  Bordeaux  mixture  gave  decidedly  the 
best  results.  Treating  the  posts,  etc.,  with  the  copper  solution, 
in  these  experiments  proved  to  be  practically  of  no  value. 

Prillieux  also  mentions l  a  case  in  which  the  Bordeaux  mixture 
again  gave  the  best  results.  Professor  Fasquelle,  of  Jura,  ap- 
plied a  4  per  cent  solution  of  copper  sulphate  to  potatoes,  and  the 
foliage  was  plainly  injured.  Bordeaux  mixture,  containing  an 
equal  amount  of  copper,  was  used  at  the  same  time  and  no  inju- 
rious effects  could  be  perceived  in  consequence  of  the  treatment. 

The  difficulty  of  applying  the  Bordeaux  mixture  when  made 
according  to  Millardet's  formula  induced  several  vineyardists  to 
vary  the  proportions  considerably,  and  the  general  impression 
at  the  close  of  the  year  1886  seemed  to  be  that  there  was  no 
necessity  for  using  so  much  copper  or  lime  to  obtain  equally  good 
results  as  followed  the  use  of  the  original  formula.  This  ques- 
tion is  not  entirely  settled  even  at  the  present  day,  and  it  is  very 
probable  that  some  diseases  require  the  use  of  more  copper  than 
others,  some  being  successfully  treated  with  very  small  amounts. 

It  was  early  in  1887  that  the  idea  was  first  advanced  of  using 
a  stock  solution  for  the  making  of  Bordeaux  mixture.2  A  cer- 
tain amount  of  copper  sulphate  is  dissolved  in  a  given  quantity 
of  water,  and  any  desired  amount  of  the  salt  can  be  obtained 
by  taking  out  the  amount  of  water  which  holds  it  in  solution. 
The  practice  is  now  also  in  use,  to  a  limited  extent,  for  meas- 
uring the  lime. 

The  necessity  of  adding  lime  to  the  copper  sulphate  solution 
was  not  generally  conceded.3  Vautier  made  comparative  tests 

i  Jour.  d'Aff.  Prat.  1886,  Dec.  16,  886. 

«  Eicaud,  J.,  Jour.  <VAg.  Prat.  18ST,  Jan.  20,  90. 

*Vignt  Americaine,  1886,  Sept.  290  et  seq. 


Copper  Sulphate  and  Ammonia.  35 

of  the  Bordeaux  mixture,  eau  celeste,  and  of  the  treatment  of 
A.  Bouchard.  This  last  treatment  consisted  in  the  use  of  300 
grams  sulphate  of  copper  dissolved  in  one  hectoliter  of  water.  His 
conculsions  were  that  there  is  no  particular  difference  between 
the  three  fungicides  as  regards  efficiency,  but  the  last  is  to  be 
preferred  on  account  of  the  ease  with  which  applications  can  be 
made,  and  the  cheapness  of  the  treatments.  These  opinions 
were  not  generally  accepted,  unless  it  was  in  Burgundy,  where 
Bouchard's  treatment  v/as  considered  an  excellent  remedy. 

The  disadvantage  of  Audoyiiaud's  eau  celeste  was  that  it 
burned  the  foliage.  On  account  of  the  ease  with  which  this 
solution  could  be  applied,  many  attempts  were  made  to  render 
it  harmless.  Michel  Pcrret,  of  Tullius,  said1  that  the  use  of 
one  part  of  ammonia  to  two  of  copper  sulphate  would  form 
a  perfectly  safe  solution.  He  said  further2  that  the  following 
formula  was  adopted  in  Isere,  where  it  was  known  under  the 
name  of  "  Bouillie  dauphinoise  " : 

Copper  sulphate 2  kilos. 

Water 20  liters. 

Ammonia  22° 1  liter. 

Allow  this  to  stand  some  hours  and  then  draw  off  the  liquid. 
This  contains  the  sulphate  of  ammonia,  which  is  supposed  to  be 
harmful  to  foliage. 

To  the  precipitate  formed  above,  add 

Sulphur 2  kilos. 

Water 100  liters. 

The  sulphur  should  first  be  mixed  with  the  precipitate  to 
form  a  paste,  and  the  water  is  then  added.  He  favored  this 
mixture  because  the  mutual  action  of  the  copper  and  the  sul- 
phur was  such  that  neither  affected  the  wine  manufactured 
from  the  grapes.  Carnot  advised 3  the  use  of  five  or  six  parts 
of  the  sulphate  of  ammonia  to  one  part  of  copper  sulphate 
crystals.  G.  de  Capol  said4  that  it  might  be  well  to  dissolve 

i  Jour  d'Ag.  Prat.  1887,  March  10,  354. 
»  IMd.  June  23,  878. 

»  Soc.  Nat.  d'Ag.  1887,  March  16.  Cited  in  Jour.  d'Ag.  Prat.  1887,  May  19. 
714. 

« Ibid.  loc.  cit. 


36  The  Spraying  of  Plants. 

in  ammonia  the  hydrates  of  copper  deposited  by  the  formula 
given  by  Ferret.  This  would  give  a  solution  entirely  free  from 
acid. 

Another  of  the  many  new  remedies  proposed  during  the  year 
1887  was  brought  forward l  by  Emile  Masson.  He  recommended 
the  use  of  the  carbonate  of  soda  and  the  sulphate  of  copper, 
and  used  these  two  materials  in  proportions  varying  from  one 
kilo  of  copper  sulphate  to  one  or  two  of  soda  carbonate,  or  sal- 
soda.  These  were  used  in  one  hectoliter2  of  water.  He  said 
that  the  fungicide  did  not  burn  foliage  and  that  it  spread  evenly. 

Dr.  G.  Patrigeon,  of  Chabris  (Indre),  France,  is  probably  en- 
titled to  the  credit  of  having  first  conceived  and  put  into  prac- 
tice the  remedy  proposed  by  Masson.  He  describes  3  it  as  the 
"treatment  of  mildew  with  the  hydrocarbonate  of  copper." 
The  substance  was  prepared  by  using 

Copper  sulphate 4  kilos. 

Carbonate  of  soda 6    " 

Water 100  liters. 

He  said  it  adhered  to  foliage  fully  as  well  as  the  Bordeaux 
mixture,  and  thought  it  could  be  used  twice  as  strong  as  recom- 
mended above. 

A  second  preparation  mentioned  by  Dr.  Patrigeon  was  made 
by  dissolving  with  ammonia  the  precipitate  formed  in  the  pre- 
ceding mixture.  The  proportions  of  the  ingredients  varied  a 
little  as  follows : 

Copper  sulphate 1  kilogram. 

Carbonate  of  soda 1      " 

Ammonia  22° 1  liter. 

Water 100  liters. 

The  first  two  ingredients  are  each  dissolved  in  four  liters  of 
water  in  separate  vessels.  The  soda  carbonate  solution  is  then 
caref  ully  poured  into  the  solution  of  copper  sulphate,  and  when 
all  reaction  has  stopped  the  ammonia  is  added.  As  soon  as  the 
precipitate  is  dissolved  the  solution  may  be  diluted  with  the 

*  Jour.  &Ag.  Prat.  1887,  June  9,  814. 

8  A  hectoliter  is  26.416  U.  S.  gallons  of  231  cu.  in. ;  or  22.009  Eng.  Imp.  gallons 
of  277.26  cu.  in. 

»  Jour.  &Ag.  Prat.  1887,  June  23,  879. 


Grape  Anthracnose.  37 

water.  Practically  this  same  solution  is  more  or  less  used  to- 
day, but  it  is  known  as  the  "modified  eau  celeste."  Patrigeon 
at  the  time  of  its  introduction,  referred  to  it  simply  under  the 
name  of  the  hydrocarbonate  of  copper  dissolved  in  ammonia. 

The  "  bouillie  berrichonne"  is  a  third  preparation  introduced 
by  Patrigeon.  This  was  made  like  the  preceding,  with  the 
exception  that  only  a  portion  of  the  copper  precipitate  was  dis- 
solved by  ammonia,  instead  of  all  of  it.  He  desired  that  only 
one-third  be  dissolved.  This  portion  would  have  an  immediate 
action  upon  fungi,  while  the  remaining  undissolved  part  would 
act  as  a  reserve  supply.  Later  investigations  have  shown  that 
such  preparations  are  unnecessary  for  the  successful  treatment 
of  fungous  diseases. 

The  anthracnose  of  grapes  was  at  this  time  receiving  consider- 
able attention.  No  reports  of  success  in  treating  the  disease 
during  the  growing  season  are  reported,  but  all  recommenda- 
tions are  to  the  effect  that  applications  should  be  made  during 
the  winter.  The  following  treatments  appeared  to  be  most 
promising.2  The  first  formula  was  proposed  by  Michel  Perret: 

1.  Copper  sulphate 10  kilos. 

Iron  "        10    " 

Water 100  liters. 

2.  The  Schnorf 3  treatment  (see  page  23)  consisted  in  applying 

Iron  sulphate 50  kilos. 

Water 100  liters. 

3.  Ordinary  Bordeaux  mixture : 

Copper  sulphate 8  kilos. 

Lime 15    " 

Water 130  liters. 

4.  The   same   as  3,  but  12  kilos  of  copper  sulphate  were 
used  instead  of  8.     This  gave  the  best  results,  but  numbers  2 
and  3  follow  closely.     The  first  proved  to  be  much  less  satis- 
factory. 

1  Jour.  VAg.  Prctf.  1887,  May  5,  641. 

*  Millardet,  "  Nouvelles  Recherches  sur  le  D6v«loppement  et  le  Traitement  du 
Mildew  et  de  1' Anthracnose,"  18S7,  56. 
« Ibid.  loc.  cit. 


38  The  Spraying  of  Plants. 

Millardet  believed  that  if  one  or  two  winter  treatments  were 
made  regularly  for  three  years,  the  anthracnose  could  be  entirely 
cured;  and  at  the  present  day  this  grape  disease  is  well  under 
control  in  Europe. 

Millardet's  formula  for  making  the  Bordeaux  mixture  in  1887 
was  as  follows  :  x 

Copper  sulphate 3  kilos. 

Quicklime 1  kilo. 

Water 100  liters. 

He  also  proposed  several  others,  but  this  is  the  one  which 
promised  the  best  results  both  as  regards  its  application  and  its 
fungicidal  value. 

In  a  comparative  trial  of  Bordeaux  mixture  and  sulpho- 
steatite  on  potatoes  and  tomatoes,  the  powder  gave  apparently 
the  best  results.2  Its  value  consisted  in  the  fact  that  it  adhered 
to  the  foliage  better  than  the  Bordeaux  mixture,  and  that  it 
reached  the  under  as  well  as  the  upper  side  of  the  leaves.  This 
is  especially  true  for  the  tomato,  and  he  advised  the  use  of  this 
powder  upon  these  two  plants. 

The  formulas  recommended  for  making  the  Bordeaux  mix- 
ture in  1888  all  mentioned  greatly  reduced  amounts  of  copper 
sulphate  and  lime.  Millardet  and  Gayon  found  3  that  by  reduc- 
ing the  amount  of  lime  the  mixture  was  rendered  more  adher- 
ent. In  their  experiments  carried  on  at  Dausac  in  1887,  a 
careful  study  was  made  of  the  effects  produced  by  the  use  of 
different  amounts  of  copper  sulphate.  The  original  formula 
contained  6  kilos  of  this  salt  in  1  hectoliter  of  the  mixture. 
Millardet  and  David  wrere  so  well  convinced  of  the  value  of 
these  more  dilute  mixtures  that  the  former  advised4  the  use 
of  only  1  kilo  in  a  hectoliter  of  water ;  but  if  a  severe  attack  of 
mildew  was  feared,  the  use  of  2  kilos  was  thought  to  be  safer. 

Eau  celeste  was  also  used  in  this  work,  but  it  proved  to  be 
inferior  to  the  Bordeaux  mixture.  This  was  found  to  be  true 
even  to  a  greater  extent  in  the  case  of  other  preparations  con- 
taining ammonia. 

i  Jour.  d'Aff.  Prat.  188T,  May  19,  704. 

J  Ibid.  June  9,  807.     See,  also,  "  Peronospora  de  la  Yigne  et  Sulpho steatite 
cuprique,"  Dr.  B.  Nabias,  1887,  Bordeaux. 
3  Ibid.  1888,  May  3,  623. 
*  Ibid.  624. 


The  Black  Rot  of  Grapes.  39 

As  regards  the  number  of  treatments  necessary  for  the  best 
and  most  economical  protection  of  the  vine,  Millardet  says 1  that 
at  least  two  must  always  be  made,  "  but  the  earlier  appearance 
of  the  disease,  its  greater  intensity,  and  rapid  spreading  may 
render  three  or  even  four  applications  necessary."  They  were 
made  in  1887  as  follows  :  June  10,  or  some  days  before  flower- 
ing, July  14,  and  August  8.  This  apparently  was  not  sufficient 
to  protect  the  vines  fully. 

The  conclusions  reached  by  Dr.  Patrigeon  in  his  work  of 
1887  were  that  the  price  of  applications  of  the  hydrocarbonate 
of  copper  dissolved  in  ammonia  (modified  eau  celeste)  was  very 
low  ;  that  the  formulas  for  the  preparation  of  the  solution  are 
remarkably  simple  and  practicable  ;  that  the  material  is  equally 
or  perhaps  even  more  efficient  than  any  other  fungicide  in  use ; 
and  that  it  is  perfectly  harmless  to  foliage.  These  claims  for  the 
merit  of  the  solution  were  indeed  founded  upon  fact,  for  it  has 
been  hard  to  decide,  in  regard  to  the  comparative  efficiency, 
between  the  Bordeaux  mixture  and  the  ammoniacal  solution  of 
the  carbonate  of  copper,  which  is  practically  the  same  as  the 
modified  eau  celeste  recommended  by  Dr.  Patrigeon. 

The  American  disease  of  grapes  commonly  known  as  black 
rot  was  first  discovered  in  the  vineyards  of  France  in  August, 
1885.  Mr.  Ricard,  the  steward  of  an  estate  situated  at  the 
gates  of  the  small  town  of  Ganges  at  the  borders  of  1'Herault, 
was  the  first  to  call  attention  to  the  presence  of  this  fungus.2 
He  saw  that  his  grapes  turned  brown,  then  black,  while  still 
remaining  upon  the  vine.  He  sent  some  of  these  diseased 
grapes  to  the  viticultural  laboratory  of  I'Ecole  de  Montpellier, 
where  Messrs.  Viala  and  Ravaz  recognized  the  parasite.  They 
went  to  the  affected  vineyard,  and  saw  that  only  about  thirty 
hectares  in  the  plain  of  Ganges  showed  diseased  grapes.  In 
these  vineyards  the  harvest  was  reduced  about  one-half. 

Immediate  and  energetic  steps  were  taken  to  exterminate  the 
fungus,  but  in  1886  it  again  appeared.  The  season  proved  to 
be  dry,  however,  and  very  little  damage  was  done.  The  area 
of  distribution  was  nevertheless  considerably  extended. 

On  July  25,  1887,  Prillieux  received  diseased  grapes  from 
Azen,  in  Lot-et-Garonne,  and  was  directed  by  the  minister 
of  agriculture  to  proceed  to  the  infected  district.  He  found 

i  Jour.  VAg.  Prat.  1888,  May  17,  694.  2  Ibid.  June  14,  84T. 


40  The  Spraying  of  Plants. 

that  black  rot  existed  throughout  the  entire  valley  of  the 
Garonne  as  far  as  Aiguillon.  In  some  vineyards  it  was  so 
well  established  that  there  appeared  to  be  no  doubt  that  the 
disease  had  been  present  at  least  a  year  before  its  discovery 
in  1'Herault ;  it  was  consequently  impossible  to  determine  the 
first  place  of  infection  in  France.  The  disease  was  new,  and 
at  the  first  not  very  serious,  so  that  its  presence  had  been  over- 
looked perhaps  for  more  than  one  year.  None  of  the  copper 
compounds  had  been  tried  to  check  the  disease,  and  this  was 
the  most  encouraging  feature  of  the  situation  in  the  fall  of 
1887.  The  outcome  showed  that  this  fact  might  indeed  give 
rise  to  a  hope  that  this  new  disease  could  be  controlled.  It 
was  in  truth  suppressed  with  greater  despatch  and  with  less 
trouble  than  the  downy  mildew  had  been,  for  on  August  2  of 
the  following  year  there  was  published  *  a  letter  from  Prillieux 
in  which  he  says:  "  When  we  see  two  rows  of  grapes,  one  en- 
tirely devastated,  the  other  preserved  by  treatment,  we  must 
feel  encouraged  for  the  future."  The  following  week  the  same 
journal  published  2  another  letter  from  Prillieux,  saying  :  "  These 
experiments  demonstrate  with  complete  certainty,  as  was  sus- 
pected, but  without  having  been  positively  established  either 
in  America,  where  the  disease  has  ravaged  vineyards  for  years, 
nor  in  France,  that  cupric  treatment  can  stop  the  invasion  of 
black  rot  as  well  as  of  mildew,  provided  applications  arc  made 
early  enough,  and  in  a  proper  manner.  The  success  in  the 
experimental  treatments  at  Aiguillon  in  a  year  favorable  to  the 
disease,  as  was  proved  by  the  complete  destruction  of  the  crop 
on  untreated  plants,  is  a  guarantee  of  success  in  the  future.  We 
can  now  combat  the  black  rot  as  effectually  as  the  mildew." 

No  other  events  of  much  importance  appear  to  have  occurred 
in  France  in  1887  or  1888.  The  use  of  more  dilute  Bordeaux 
mixture  was  not  followed  by  such  uniformly  good  results  as 
was  hoped.  Several  vineyardists  recommended  a  mixture  which 
should  contain  not  less  than  3  kilos  copper  sulphate  in  1  hecto- 
liter of  the  mixture,  and  it  was  thought  advisable  to  make 
it  even  stronger  for  the  first  application.  Many  were  also  in 
favor  of  using  only  2  kilos.  Burning  of  the  foliage  had  resulted 
from  some  applications,  and  this  led  to  the  advice  of  using  at 
least  equal  parts  by  weight  of  quicklime  and  copper  sulphate. 

i  Jour.  d'Ay.  Prat,  1888,  Aug.  2,  151.  *  Ibid.  Aug.  9,  195. 


Solutions  of  Copper  in  Fimgicides.  41 

The  Bordeaux  mixture  still  retained  its  supremacy  wherever 
it  was  used  in  comparative  trials.  Prillieux  made  one  of  the 
most  satisfactory  tests  in  this  direction  in  his  work  on  the 
black  rot  in  1888.1  He  used,  in  addition  to  the  Bordeaux  mix- 
ture, eau  celeste,  pure  solutions  of  copper  sulphate,  sulphostea- 
tite,  and  Carrere  powder.  The  relative  value  of  these  materials 
was  in  the  same  order  as  they  are  here  mentioned.  The  vines 
treated  with  the  powders  were  attacked  by  the  disease  appar- 
ently as  much  as  those  which  had  received  no  treatment.  The 
dates  of  treatment  apparently  had  some  effect  on  the  efficiency 
of  all  the  materials.  The  first  applications  seem  to  have  been 
made  too  late,  for  Frechou  said2  he  had  obtained  excellent 
results  from  the  use  of  sulphosteatite  and  also  of  the  Carrere 
powder.  Lasserre  controlled 3  the  black  rot  well  by  applying 
only  1  kilo  copper  sulphate  and  1|  liters  ammonia  in  1  hecto- 
liter of  water.  His  first  treatments  were  made  April  28,  and 
he  ascribes  his  success  to  the  timely  beginning  of  the  work. 
He  believed  that  the  success  of  Prillieux  might  have  been 
even  more  complete  if  his  applications  had  been  made  earlier 
in  the  season. 

During  1889  a  new  problem  was  occupying  the  minds  of  the 
leading  French  experimenters.  It  was  the  general  belief  that 
the  Bordeaux  mixture  was  too  slow  in  its  action,  since  practi- 
cally none  of  the  copper  contained  in  it  was  soluble  in  pure 
water.  Another  reason  was  advanced  for  this  tardy  action  of 
the  Bordeaux  mixture:  Millardet  and  Gayon  said4  that  no  cop- 
per could  be  absorbed  by  foliage  until  all  the  excess  of  lime 
had  been  formed  into  the  carbonate.  This  process  was-  sup- 
posed to  require  from  a  week  to  a  week  and  a  half.  They 
said 5  that  the  change  took  place  faster  during  a  fine  rain,  bufc 
even  then  it  appeared  that  the  immediate  action  of  the  mixture 
as  soon  as  applied  was,  at  the  best,  but  very  slight.  The  greater 
the  excess  of  lime,  the  longer  appeared  to  be  the  time  required 
for  the  copper  to  enter  into  solution. 


1  Jour.  d'Ag.  Prat.  1S83,  Dec.  20,  898. 

2  Ibid.  Dec.  13,  851. 

3  Ibid.  loc.  cit. 

*  Ibid.  1890,  Feb.  20,  -27-2. 

5  "  Nouvelles  Recherches  sur  le  Developpement  et  le  Traitement  du  Mildiou  et 
de  TAnthracnose,"  Millardet  et  Gayon,  1887,  8-18. 


42  The  Spraying  of  Plants. 

Millardet  and  Gayon  in  1887  conceived1  the  idea  of  making 
the  Bordeaux  mixture  on  a  new  plan.  This  consisted  in  leav- 
ing about  the  tenth  of  one  per  cent  of  dissolved  copper  sulphate 
in  the  mixture.  As  comparatively  little  was  heard  of  this  prep- 
aration, it  is  probable  that  the  difficulty  of  its  preparation  was 
one  reason  why  it  was  not  more  extensively  used.  But  others 
were  at  work  upon  the  problem  and  it  was  eventually  solved. 

B.  Pons,  a  chemist  at  Limoux  (Aude),  worked  at  it  from  a 
chemical  standpoint.2  He  took  advantage  of  the  fact  that  when 
concentrated  solutions  of  sugar  and  of  copper  sulphate  are 
mixed  with  each  other,  there  is  eventually  formed  a  precipitate 
which  is  a  true  sulphosaccharate  of  copper.  This  precipitate, 
when  dry,  is  in  the  form  of  a  very  fine,  bluish-white  powder. 
Pons  modified  it  in  such  a  manner  that  the  amount  of  dis- 
solved copper  in  the  Bordeaux  mixture  could  be  regulated  by 
the  varying  amounts  of  the  powder  used.  His  directions  for 
preparing  the  mixture  were  as  follows: 

Dissolve  2  kilos  of  this  powder  in  90  liters  of  cold  water. 
Agitate  for  five  to  fifteen  minutes.  Add  to  this  liquid,  while 
stirring  well,  1  kilo  of  quicklime  freshly  slaked  in  10  liters  of 
water.  Stir  the  mixture  for  about  five  minutes  and  it  is  then 
ready  for  use.  At  first  it  entirely  resembles  the  Bordeaux  mix- 
ture as  commonly  prepared,  but  when  this  precipitate  is  allowed 
to  settle  the  liquid  above  the  sediment  is  of  a  blue  color,  whereas 
in  the  common  Bordeaux  it  is  clear.  One-fourth  of  the  copper 
contained  in  the  mixture  is  held  in  solution  in  this  "  Bordeaux 
mixture  celeste  " ;  the  preparation  was  so  called  by  Pons. 

Pons  sent  some  of  this  powder,  which  he  called  the  sulpho- 
saccharate of  copper,  to  Millardet  and  Gayon  in  October,  1889, 
for  the  purpose  of  having  it  tested.3  They  described  it  as  a 
blue  powder,  as  fine  as  ashes,  but  homogeneous  in  character. 
When  prepared,  the  mixture  was  very  alkaline,  and  the  pre- 
cipitate was  finer  and  more  abundant  than  that  found  in  the 
Bordeaux  mixture.  On  this  account  the  solid  matter  settled 

1  Millardet  et  Gayon,  "  Considerations  raisonnees  sur  les  divers  Precedes  de 
Traitement  du  Mildiou  par  les  composes  cuivreux,"  1887,  14.    See,  also,  E.  Mach, 
"  Bericht  uber  die  Ergebnisse  der  im  Jahr  1886  ausgefuhrten  Versuche  zur  Bekamp- 
fung  der  Peronospora,"  1887,  20. 

2  Jour.  d'Ag.  Prat.  1889,  Dec.  12,  866.    See,  also,  Barreswil,  Jour,  de  Pharm, 
acie  et  de  Chemie,  3me  serie,  vii.  1846,  29. 

»  Ibid.  1890,  Feb.  20,  269. 


Sugar  and  the  Bordeaux  Mixture.  43 

very  slowly  and  the  use  of  an  agitator  was  almost  unnecessary. 
When  applied  to  the  leaves,  the  preparation  was  very  similar 
to  the  Bordeaux  mixture  in  appearance.  It  adhered  to  the 
foliage  equally  well,  and  although  a  large  amount  of  copper 
was  in  solution, — 240  grams  per  hectoliter,  —  the  foliage  was  in 
no  case  burned.  These  points  appear  to  have  been  very  thor- 
oughly tested  the  same  year,  for  the  leaves  often  remain  on  the 
vines  until  the  end  of  November. 

Michel  Ferret  was  another  who  made  use  of  this  mutual 
action  of  sugar  and  copper.  He  announced  in  a  meeting  of  the 
Societe  Xationale  d'Agriculture  de  France  held  Nov.  27,  1889 
(page  604  of  the  proceedings),  that  in  cases  of  rapid  invasion 
of  the  mildew  the  action  of  the  Bordeaux  mixture  was  too  slow. 
He  maintained  that  some  copper  should  always  be  in  solution, 
and  said  that  he  had  obtained  the  desired  result  by  means  of 
sugar  or  molasses.  He  used  the  following  formula : 

Copper  sulphate 2  kilos. 

Carbonate  of  soda 3    " 

Water 15  liters. 

The  copper  sulphate  was  dissolved  in  the  water,  and  the  soda 
crystals  were  then  added.  When  the  precipitation  of  the  copper 
ceased,  there  was  added  to  the  above 

Molasses 200-500  grams. 

The  mixture  was  then  allowed  to  stand  twelve  hours,  and 
then  Ferret  added 

Water 1  hectoliter. 

The  finished  mixture  is  of  a  deep  green  color  and  is  very  ad- 
hesive. His  experiments  of  that  year  showed  that  this  new 
mixture  preserved  the  vines  better  than  any  other  in  use  at  the 
time.  In  a  letter  written  later,1  Ferret  says  that  it  suffices  to 
use  200  grams  of  molasses,  or  one-tenth  of  the  weight  of  copper 
sulphate,  to  render  soluble  the  amount  of  copper  oxide  necessary 
for  the  rapid  action  desired.  If  a  larger  amount  of  molasses  be 
added,  the  effect  is  simply  to  increase  the  amount  of  dissolved 
copper. 

i  Jour.  d'Aff.  Prat.  1S90,  Jan.  30,  183. 


44  The  Spraying  of  Plants 

It  was  stated l  by  Patrigeon  that  the  addition  of  500  grams 
of  dextrine  per  hectoliter  of  those  fungicides  having  a  solution 
of  copper  carbonate  for  their  principal  ingredient,  would  render 
them  more  adhesive.  The  dextrine  should  first  be  dissolved  in 
warm  water,  and  then  added  to  the  copper  solution. 

George  Bencker  gives  an  account  of  the  treatments  for  mil- 
dew as  carried  on  in  1890,  at  the  School  of  Agriculture,  at 
Montpellier,  France.2  The  experiments  were  conducted  by 
Duchien.  The  list  of  substances  used  is  interesting  from  the 
fact  that  it  shows  which  materials  the  French  at  that  time  con- 
sidered as  having  value.  The  liquids  tested  were  as  follows : 

Bordeaux  mixture;  Bordeaux  mixture  celeste,  containing 
copper  sulphate,  lime,  sugar,  and  aluminum  calcide ;  Bordeaux 
mixture  and  glue  ;  mixture  of  carbonate  of  soda  and  sulphate 
of  copper;  gelatinous  hydrocarbon  ate  of  copper;  verdet ;  and 
a  mixture  of  chloride  of  calcium  and  alum.  The  powders : 
Skawinski's  powder;  Skawinski's  sulphur;  cuprosteatite ;  sul- 
phosteatite ;  sulphocyanide  of  copper ;  sulpfaated  verdet ;  sulphur 
with  the  hydrate  of  copper;  sulphated  sulphur;  cuprophos- 
phate  ;  8  and  sulphur  and  cuprophosphate. 

Verdet  was  selected  as  being  the  most  valuable  of  the  above 
materials,  but  later  work  has  not  substantiated  this  conclu- 
sion. Verdet  is  an  acetate  of  copper.  There  are  many  such 
combinations,  all  being  known  under  the  general  name  of  ver- 
det, or  verdigris.  The  form  used  by  Bencker  was  that  techni- 
cally known  as  the  dibasic  acetate  of  copper.  It  requires  to  be 
soaked  in  water  three  or  four  days  before  it  is  used,  so  that  as 
milch  as  possible  will  dissolve.  It  may  be  applied  at  the  rate 
of  one  or  two  kilos  in  a  hectoliter  of  water. 

De  Capol  prepared  the  hydrate  of  copper  as  follows:4  Dis- 
solve 2  kilos  of  copper  sulphate  in  20  liters  of  water.  To  this 
add  1  liter  ammonia.  The  oxide  of  copper  is  precipitated,  and 
when  it  has  settled  to  the  bottom  of  the  vessel  the  liquid  above 
is  drawn  off.  This  liquid  contains  sulphate  of  ammonia  iu 

1  RuUetin  de  la  Societe  des  Agriculteurs  de  Fi  ance,  1889,  Oct.  15,  795.    Also, 
Jour.  d'Ag.  Prat.  1890,  May  15,  703. 

2  Progres  Agrieole,  1890,  Dec.  7,  510;  Annals  Hort.  1890,  82. 

3  This  material  is  easily  made  by  uniting  solutions  of  sodium  phosphate  and 
copper  sulphate.     It  is  thrown  down  as  a  precipitate,  the  other  compounds  remain- 
ing in  solution. 

*  Jour.  d'Ag.  Prat.  1889,  March  7,  367- 


The  Use  of  Sulphuric  Acid.  45 

solution,  and  should  be  used  for  fertilizing  purposes.  The  pre- 
cipitate is  then  treated  with  10  liters  of  ammonia  and  there  is 
obtained  a  normal  solution.  Dilute  forty  times  when  applying. 
De  Capol  believed  this  to  be  an  excellent  preventive  against  the 
mildew,  and  he  also  said  that  it  would  not  burn  the  foliage. 
The  preparation,  however,  never  came  into  general  use. 

Messrs.  Skawinski  were  among  the  first  in  France  to  use 
Schnorf 's  remedy  for  anthracnose.  But  their  experience  sug- 
gested to  them  a  change  in  the  preparation,  which  led  to  a 
general  modification  of  the  old  formula.  They  remarked  that 
the  action  of  the  iron  sulphate  was  stronger  when  sulphuric 
acid  was  present  in  considerable  quantities  with  the  crystals. 
They  consequently  adopted  the  following: 

Iron  sulphate 50  kilos. 

Sulphuric  acid,  53°i 1  liter. 

Warm  water 1  hectoliter. 

The  best  method  of  making  the  solution  is  to  pour  the  acid 
upon  the  crystals  of  iron  sulphate,  and  then  slowly  to  add  the 
water.  The  amount  to  be  used  during  the  day  is  made  in 
the  morning ;  if  the  material  is  allowed  to  stand  for  twenty- 
four  hours  or  more  the  salt  re-crystallizes,  and  the  applications 
will  not  be  so  efficacious.  Skawinski  washed  the  grape  wood 
once  during  the  first  days  of  February.  The  immediate  effect 
upon  the  wood  is  to  blacken  it,  and  if  this  color  is  not  uni- 
formly shown,  a  second  application  is  made  to  those  portions 
which  were  not  touched  by  the  first  treatment.  The  above 
formula  has  not  been  uniformly  adopted  in  France,  for  some 
growers  prefer  to  increase  the  amount  of  acid,  and  others  de- 
crease the  amount  of  iron  salt.  But  as  the  practice  of  spraying 
with  such  a  solution  has  been  well  established,  and  since  good 
results  generally  follow  the  treatment,  it  is  safe  to  say  that  so 
long  as  the  plants  are  uninjured,  the  use  of  a  definite  formula 
is  of  minor  importance. 

In  1890  Dr.  G.  Patrigeon  gave  the  following  directions  re- 
garding the  treatment  of  grape  mildew.2  He  advised  that  the 
first  application  be  made  about  the  middle  of  May  in  southern 
France,  and  during  the  first  week  in  June  in  the  more  northern 

1  This  grade  of  acid  was  used  because  it  is  less  dangerous  to  handle. 
*  Jour.  d"Ag.  Prat,  1890,  May  8,  660. 


46  The  Spraying  of  Plants. 

parts  of  the  country.  The  second  treatment  should  be  made 
three  weeks  later,  and  a  third  again  in  three  or  four  weeks.  In 
case  of  necessity  a  fourth  should  be  made  early  in  September. 
He  further  advised  that  the  material  should  be  applied  lavishly, 
during  the  first  treatment  in  particular,  and  that  the  leaves 
should  be  thoroughly  covered.  He  also  said  that  it  should  be 
made  a  point  to  cover  the  young  grapes,  a  recommendation 
which  does  not  appear  to  have  been  made  before.  When  the 
Bordeaux  mixture  was  first  coming  into  use,  Millardet  said  one 
should  be  careful  not  to  strike  the  grapes,  and  he  also  made  the 
statement  that  if  only  a  small  amount  of  the  mixture  fell  upon 
the  leaf  it  would  still  afford  ample  protection.  Experience  evi- 
dently had  shown  that  the  work  cannot  be  done  too  thoroughly. 

Patrigeon  did  not  favor  the  use  of  powders  for  the  following 
reasons  :  they  require  moist  foliage  to  adhere  well ;  they  can  be 
applied  only  when  the  air  is  still ;  more  applications  have  to  be 
made  ;  and  the  vines  are  not  so  well  protected.1 

He  considered  as  entirely  unfit  for  use  upon  foliage  the  simple 
solution  of  copper  sulphate,  and  the  eau  celeste  of  Audoynaud, 
because  they  burned  the  leaves.  The  materials  which  could  be 
advantageously  applied  were  reduced  to  those  mixtures  or  solu- 
tions that  contain  copper  in  the  form  of  the  hydrate  (hydrate 
oxide)  or  of  the  hydrocarbon  ate.  There  were  several  of  these 
already  in  use. 

Patrigeon  was  the  first  to  use  and  to  advise  the  use  of  the 
ferrocyanide  of  potassium  as  a  test  for  determining  the  proper 
amount  of  lime  required  in  making  the  Bordeaux  mixture.2 
His  directions  were  to  add  to  the  Bordeaux  mixture  a  few 
drops  of  a  20  per  cent  solution  of  this  chemical.  So  long  as 
dissolved  copper  exists  in  the  mixture,  the  addition  of  the 
ferrocyanide  of  potassium  causes  a  reddish  brown  precipitate 
to  appear.  Lime  should  be  added  till  no  change  takes  place 
when  the  reagent  is  added.  Some  vineyardists  used  blue 
litmus  paper  for  the  same  purpose.3 

During  these  years  the  diseases  which  affect  grapes  received 
by  far  the  most  attention.  Jouet  and  Prillieux  were  among 

1  Jour.  &Ag.   Prat.   1890,  May  8,   660.      See  also,    "Reunion  publique  des 
Viticulteurs  du  Midi,"  held  at  Montpellier,  March  4,  1890. 
*  Ibid.  May  15,  701. 
»  A.  Petit,  Le  Progrte  Agricole,  1890,  June  1,  441. 


Adhesive  Properties  of  Fungicides.  47 

the  first  to  use  the  remedies  (see  page  29)  on  other  plants,  and 
some  experimenters  soon  followed  their  example.  Aime  Girard 1 
in  1888  and  1889  made  some  very  conclusive  experiments  upon 
the  potato.  Among  the  points  emphasized  by  him  may  be 
mentioned  the  fact  that  curative  applications  do  not  assure 
complete  immunity ;  he  also  noticed  that  there  was  a  great 
difference  in  the  varieties  as  regards  their  susceptibility  to  the 
disease. 

Chatrin  applied  the  Bordeaux  mixture  to  pears  in  1890 2  for 
a  disease  commonly  known  as  "  tavelure."  It  is  caused  by  a 
fungus,  Fusicladium  pyrinum,  and  his  applications  are  said  to 
have  been  followed  by  good  results.  Another  fungous  disease 
commonly  known  as  "  cloque,"  probably  due  to  some  species  of 
Taphrina  or  Exoascus,  was  receiving  attention.8  The  trouble 
is  mentioned  as  affecting  peach  trees.  It  causes  the  leaves  to 
curl  in  a  manner  similar  to  that  which  is  only  too  frequently 
seen  in  America.  Lesne  advised  growers  to  spray  their  trees 
with  the  Bordeaux  mixture,  but  this  recommendation  does  not 
appear  to  have  been  founded  upon  successful  work. 

Aime  Girard4  conducted  some  experiments  to  test  upon 
potato  foliage  the  adhesive  powers  of  various  fungicides.  His 
conclusions  are  as  follows : 

"  1.  Copper  compounds  adhere  to  foliage  with  different  de- 
grees of  persistence. 

"  2.  Under  the  action  of  severe  rains,  copper  disappears 
largely  on  account  of  the  mechanical  action  of  the  water. 

"  3.  Among  these  compositions  the  one  which  washes  the  most 
is  the  Bordeaux  mixture  of  various  formulas.  The  diminution 
of  the  proportion  of  lime  augments  a  little  the  adhesive  power ; 
but  the  addition  of  aluminous  materials  does  not  produce  any 
sensible  amelioration. 

"4.  The  precipitated  carbonate  of  copper  (bouillie  cupro- 
sodique)  on  the  one  hand,  and  verdet  on  the  other,  have  the 
faculty  of  adhering  almost  twice  as  wrell  as  the  Bordeaux  mix- 
ture. But  above  all  others  Ferret's  mixture  of  copper,  lime, 
and  sugar  [see  page  43]  resists  the  action  of  rains  remarkably 
well.  Therefore  the  last  is  to  be  preferred,  other  things  being 
equal,  and  its  use  is  advised." 

1  Jour.  d'Ag.  Prat.  1890,  June  5,  803.  »  Ibid.  1891,  May  21,  736. 

*  Ibid.  Nov.  20,  755.  *  Ibid.  1892,  Feb.  4,  177. 


48  The  Spraying  of  Plants. 

In  1891  Millardet  and  Gayon  also  made  a  comparative  test 
of  various  fungicides.1  Their  work,  however,  did  not  consider 
mainly  the  adhesive  power  of  the  fungicides,  but  rather  their 
general  efficiency.  During  1890  they  applied  the  sulphosaccha- 
rate  of  copper  of  B.  Pons  (see  page  42).  The  downy  mildew  was 
not  sufficiently  severe  to  show  the  value  of  the  fungicide  and 
no  report  could  be  made.  In  1891  Pons  sent  another  prepara- 
tion to  Millardet  and  Gayon,  this  being  known  under  the  con- 
venient term  "  bouillie  bordelaise  celeste  a  poudre  unique"  It 
was  in  the  form  of  a  very  fine  blue  powder,  and  was  composed 
essentially  of  the  powder  of  Bordeaux  mixture  celeste,  sulphate 
of  copper,  the  carbonate  and  the  bicarbonate  of  soda. 

The  amount  of  the  powder  used  per  hectoliter  of  water  was 
two  kilos,  this  containing  exactly  one  kilo  of  copper  sulphate. 
The  powder  was  added  to  the  water,  was  thoroughly  stirred, 
and  then  applied.  The  material  is  so  fine  that  it  settles  very 
slowly,  probably  not  before  twenty-four  hours ;  the  liquid 
above  it  is  blue  and  contains  a  little  more  than  one-tenth  of 
the  total  amount  of  copper  in  solution  in  the  form  of  the  bi- 
carbonate. 

The  above  preparation  was  used  in  comparison  with  the 
following :  the  Bordeaux  mixture  as  commonly  made  (see  page 
40),  Bordeaux  mixture  celeste  (see  page  42),  Bourguignonne 
mixture  (see  page  32),  Berrichone  mixture  of  Dr.  Patrigeon  (see 
page  37),  Bordeaux  mixture  and  the  sulphate  of  ammonia,  and 
Bordeaux  mixture  and  glue  (see  page  28).  The  results  of  these 
applications  were  as  follows  : 

"  1.  All  the  mixtures,  containing  equal  amounts  of  copper, 
have  shown  an  equal  degree  of  efficiency,  and  the  attack  of 
mildew  was  severe.  The  mixture  containing  the  sulphate  of 
ammonia  burned  the  foliage  occasionally  and  is  therefore  more 
uncertain  in  its  action  than  are  the  others. 

"  2.  The  mixtures  which  contain  copper  in  a  state  of  solution 
do  not  appear  to  be  more  active  than  the  common  Bordeaux 
mixture  and  the  Bourguignonne  mixture,  each  of  which  con- 
tains none.  In  no  case  was  there  for  some  time  a  hard  rain 
after  the  applications,  a  circumstance  which  should  diminish 
the  .efficiency  of  these  two  preparations,  and  augment  compar- 
atively the  efficiency  of  the  others. 

1  Jour.  tfAg.  Prat.  1892,  Feb.  18,  231. 


Latest  French  Methods.  49 

"  3.  The  bouillie  bordelaise  celeste  a  poudre  unique  is  as 
effective  as  the  others.  This  is  an  important  point,  for  the 
mixture  is  easily  prepared  and  it  dispenses  entirely  with  lime, 
which  is  the  main  objection  to  the  Bordeaux  mixture. 

"  4.  The  use  of  one  kilo  of  copper  sulphate  in  these  mixtures 
is  not  sufficient  for  obtaining  the  best  results  in  treatments 
similar  to  those  just  mentioned.  If  more  of  the  sulphate  is  not 
used,  a  larger  number  of  applications  must  be  made,  or  more 
material  used  at  each  application." 

A  case  is  mentioned 1  in  which  applications  of  sulphosteatite 
were  followed  by  as  good  results  as  could  be  expected  from  the 
use  of  the  Bordeaux  mixture.  At  Xorbonne,  Cenon,  and  in 
other  portions  of  France  near  Bordeaux,  this  powder  had 
been  regularly  used  for  years  in  the  prevention  of  mildew,  and 
it  proved  to  be  very  efficient  in  preserving  the  fruit  as  well  as 
the  foliage  of  the  vine,  even  during  seasons  when  untreated 
plants  lost  all  their  leaves.  At  the  estate  of  Andoque  de 
Seriege,  near  Xorbonne,  the  powder  was  applied  throughout 
the  vineyards  in  connection  with  sulphur.  In  this  manner 
both  the  downy  mildew  and  the  oidiurn  were  simultaneously 
treated.  Some  growers  in  this  region  used  the  Bordeaux  mix- 
ture early  in  the  season,  and  sulphosteatite  for  later  applications. 

At  present  but  little  experimental  work  is  being  done  with 
fungicides  in  France.  The  Bordeaux  mixture  has  become  by 
far  the  most  popular  fungicide,  and  there  are  now  no  indica- 
tions of  a  superior  article  to  replace  it.  Fungous  diseases  do 
not  appear  to  be  so  generally  severe  in  Europe  as  in  America, 
and  this  accounts  for  the  fact  that  grapes  and  potatoes,  which 
are  the  plants  most  seriously  attacked,  are  the  only  ones  gener- 
ally treated.  Applications  are  made  upon  other  plants  as  well, 
but  only  to  a  limited  extent,  and  for  less  serious  diseases. 

The  vineyards  of  France  commonly  receive  the  following 
applications,  the  work  being  considered  as  a  regular  duty,  co- 
ordinate with  cultivation  or  pruning.  It  is  an  established  fact 
that  the  vines  must  be  sprayed,  and  the  work  is  done  essentially 
as  follows.  Three  or  four  applications,  depending  upon  the 
season,  are  considered  sufficient : 

1.  The  vines  are  sprayed  wrhen  in  blossom,  or  soon  after,  with 
the  Bordeaux  mixture. 

i  Jour.  d'Ag.  Prat.  1892,  Feb.  18,  231. 


50  The  Spraying  of  Plants. 

2.  The  application  is  repeated  in  four  or  five  weeks. 

3.  The  mixture  is  applied  within  three  to  six  weeks  after  the 
second  treatment.     If  the  weather  is   inclined  to  be  wet,  a 
shorter  interval  is  allowed  between  the  two. 

4.  A  fourth  application  is  not  regularly  made.     In  case  of  a 
wet  season  it  is  made  three  or  four  weeks  after  the  third.     A 
fifth  treatment  is  rarely  thought  necessary. 

Insecticides. 

The  insecticides  in  use  in  France  during  these  years  are,  with 
few  exceptions,  still  of  the  same  general  character  as  those  used 
in  the  past.  Black  soap  was  very  commonly  employed.  It 
was  recommended,1  in  connection  with  amylic  alcohol,  for  the 
destruction  of  the  "puceron  lanigere"  (woolly  aphis).  The 
formula  given  is : 

Black  soap 35  grams. 

Amylic  alcohol 60     " 

Water 1  liter. 

Dissolve  the  soap  in  the  water  and  then  add  the  alcohol.  The 
material  was  applied  by  means  of  a  broom  or  a  syringe.  The 
alcohol  was  sometimes  replaced  by  10  percent  of  phenic  acid,  this 
and  the  soap  forming  an  emulsion. 

Other  recommendations  for  the  destruction  of  the  same  insect 
have  also  been  made.2  In  addition  to  the  black  soap  wash  are 
mentioned : 


Aloes 4  grams. 

Water..  ..1  liter. 


Also, 

Oxalic  acid 15  grams. 

Water 1  liter. 

And  another,  a  commercial  preparation : 

Insecticide  Fichet 250-300  grams. 

Water 10  liters. 

*  Jour.  d'Ag.  Prat.  1887,  May  12,  680.  *  Ibid.  June  30,  923. 


Insecticides.  51 

The  most  important  additions  to  the  list  of  insecticides  made 
in  France  were  American  remedies.  During  1884,  Professor 
C.  V.  Riley  of  the  Agricultural  Department  at  Washington, 
visited  France,  and  in  an  address  delivered  before  the  Societe 
Centrale  d'Agriculture  de  1'Herault,  June  30,  1884,  he  spoke  of 
the  emulsions  of  kerosene  with  milk  or  soap,  of  the  arsenites 
as  used  in  America,  and  of  pyrethrum.1  The  formula  for  mak- 
ing the  first  preparation  was  as  follows : 

Petroleum 8  liters. 

Common  soap 175  grams. 

Water 4  liters. 

Dilute  with  water  as  experience  may  suggest.  The  directions 
were  slightly  modified  in  later  years,  but  on  the  whole  this 
remedy  was  soon  widely  used  in  France. 

Although  the  attention  of  experimenters  was  more  particu- 
larly directed  towards  the  fungous  diseases  of  plants,  various 
other  insecticides  were  tested. 

For  large  caterpillars,  Leizour  advised  the  use  of 

Water 25  liters. 

Sulphide  of  potassium 100  grams. 

Black  soap , 250      " 

The  soap  and  the  sulphide  of  potassium  are  separately  dis- 
solved in  a  few  liters  of  water.  The  twTo  are  mixed,  and  the 
remaining  amount  of  water  is  added  immediately  before  the 
applications  are  made. 

A  remedy  supposed  to  be  particularly  valuable  for  the  de- 
struction for  the  woolly  aphis  was  made  by  taking, 

"Water 100  grams. 

Benzine '. 50      " 

Strong  glue 10      " 

This  was  to  be  applied  in  March  and  April.  A  decoction  of 
datura  plants,  when  used  with  the  sulphate  of  iron,  was  also 
recommended,  as  well  as  amylic  alcohol  and  soap  water.2 

Another  preparation  of  a  more  complicated  character  was 
recommended  for  the  same  insects.  Chemicals  having  proved 

1  Messager  Agricole,  1884,  July  10,  255. 
*  Jour.  &Ag.  Prat.  1890,  June  19,  901. 


52  The  Spraying  of  Plants. 

so  valuable  in  the  destruction  of  fungi,  it  was  probably  sup- 
posed that  some  material  could  be  found  which  would  bear 
the  same  relation  to  insects  that  the  copper  compounds  do  to 
the  mildew.  The  idea  was  certainly  a  good  one,  but  since  no 
such  substance  at  that  time  in  general  use  by  the  French  has 
remained  as  a  leading  remedy,  their  new  introductions  appear 
to  have  been  at  least  only  partially  successful.  The  use  of  the 
following  formula  was  advised  : 

Salicylic  acid 2  grams. 

Red  oxide  of  mercury 2      " 

Pyrolignic  acid 1000      " 

The  above  was  diluted  with  30  parts  of  water  when  applied. 

The  cochylis  (Cochylis  roserana)  is  an  insect  which  often  does 
much  damage  in  French  vineyards,  as  it  feeds  upon  the  leaves 
and  the  inner  portions  of  the  berries.  One  preparation  which 
was  recommended1  for  its  destruction  is  made  as  follows: 

Carbonate  of  soda 100  grams. 

Rain  water 1  hectoliter. 

When  dissolved  add  to  the  solution  a  mixture  of 

Carbon  bisulphide 1  part. 

Oil  (Colsa,  etc.) 1    " 

The  last  two  ingredients  form  an  oleo-sulphide  of  carbon,  10 
liters  of  which  are  poured  into  each  hectoliter  of  the  carbonate 
of  soda  solution,  thus  forming  an  emulsion  of  carbon  bisul- 
phide. Quantin,  director  of  the  agricultural  laboratory  of  Loiret, 
said  he  had  freed  his  vines  of  the  cochylis  by  means  of  the 
above  remedy. 

A.  Lesne  2  tried  experiments  with  eighty  preparations  for  the 
destruction  of  the  cochylis.  His  work  showed  that  a  prepara- 
tion of  pyre  thrum  and  soap  gave  the  best  results.  He  had  it 
tested  by  thirty-seven  vineyardists  and  most  of  them  reported 
favorably  regarding  it.  The  ingredients  used  were 

Black  soap 3       kilos. 

Warm  water 10       liters. 

Pyrethrum  powder 1-1^  kilos. 

1  Jour.  d'Ag.  Prat.  1891,  Aug.  6,  209.  2  Ibid.  1892,  May  5,  639. 


Present  Methods  in   Continental  Europe.       53 

The  pyrethrum  is  added  to  the  soap  solution  and  the  two  are 
well  stirred ;  90  liters  of  cold  water  are  then  put  in,  and  the 
mixture  is  ready  for  use. 

Many  other  preparations  were  made,  but  they  were  composed 
principally  of  the  ingredients  mentioned  above,  although  the 
combinations  and  the  proportions  varied  more  or  less ;  petro- 
leum, however,  is  very  often  mentioned  in  them. 

The  arsenites  have  not  as  yet  been  applied  to  any  consider- 
able extent,  and  the  use  of  pyrethrum  has  been  limited,  yet  the 
time  may  come  when  the  former  will  be  applied  as  freely  as  is 
now  done  in  America. 

II.   IN  ITALY. 

Italian  horticulturists  have  followed  the  French  so  closely  that 
little  can  be  said  concerning  the  discovery  of  new  methods  in 
Italy.  Milk  of  lime  gave  great  promise  during  the  first  year  of 
the  invasion  of  the  downy  mildew,  as  already  mentioned  on  page 
20.  But  this  substance  was  soon  replaced  by  the  copper  com- 
pounds, and  the  French  methods  were  adopted  almost  as  early 
as  they  were  in  France.  At  present,  the  Bordeaux  mixture  is 
also  the  standard  fungicide  in  Italy,  and  sprayed  vines  can 
everywhere  be  seen  during  the  summer  months. 

Italian  chemists  have$  however,  taken  the  lead  in  the  study  of 
the  various  materials  used  as  fungicides,  and  the  principal  re- 
sults of  their  work  of  this  nature  will  be  found  in  the  chapter 
treating  of  the  materials  and  formulas  used  in  spraying. 

III.  IN  OTHER  CONTINENTAL  EUROPEAN  COUNTRIES. 

The  European  mildew  of  the  grape  (Oidium  Tuckeri)  is  said1 
to  have  been  introduced  from  England  into  Germany  about 
forty  years  ago,  and  from  there  it  spread  to  France,  the  Tyrol, 
and  Italy,  causing  much  damage.  The  remedy  generally  adopted 
was  to  apply  flowers  of  sulphur  upon  the  fruit  and  foliage,  and 
this  proved  effectual  in  preventing  its  ravages. 

The  downy  mildew,  however,  was  introduced  into  Europe  by 
way  of  southern  France.  Although  it  was  rapidly  disseminated, 

i  Held,  "  Weinbau,"  1894,  125. 


54  The  Spraying  of  Plants. 

the  proper  remedies  for  its  control  were  soon  found,  and  as  the 
disease  became  more  widely  distributed,  the  best  remedies  dis- 
covered in  the  region  first  attacked  were  adopted  by  the  newly 
infected  districts,  with  practically  no  modification.  It  has  thus 
been  brought  about  that  the  Bordeaux  mixture,  the  ammoniacal 
solution  of  copper  carbonate,  the  eau  celeste,  and  solutions  of 
copper  sulphate,  have  become  standard  remedies  in  those  coun- 
tries which  have  been  last  to  suffer  from  the  imported  American 
diseases.  These  fungicides  are  generally  applied  as  in  France. 
In  Germany,  however,  care  is  taken  that  no  applications  are  made 
during  the  blossoming  period,  and  there  seem  to  be  good  reasons 
for  the  practice.  Later  applications  are  made  often  enough  to 
prevent  injury  from  fungi,  the  numbers  varying  from  two  to 
five,  three  being  more  commonly  made.  Anthracnose  of  the 
vine  is  treated  as  in  France,  and  appears  to  be  held  under  con- 
trol without  much  difficulty. 

Confidence  has  thus  again  been  restored  where  not  more  than 
ten  years  ago  there  prevailed  the  greatest  anxiety  regarding 
the  future  of  the  grape  industry. 


IV.   IN  ENGLAND. 

The  English  have  been  slow  to  adopt  new  remedies  for  plant 
diseases.  While  French  growers  were  struggling  to  overcome  the 
downy  mildew  of  the  grape  and  the  rot  of  potatoes,  British  gar- 
deners were  practically  helpless  in  dealing  with  them.  Even  after 
success  had  rewarded  their  southern  neighbors,  the  new  methods 
were  but  slowly  adopted  in  England.  The  horticultural  jour- 
nals of  that  country,  on  the  contrary,  were  quick  to  see  the  value 
of  the  work  that  was  being  done,  and  the  French  recommenda- 
tions were  repeatedly  published.  The  first  account  appears  to 
have  been  given  in  The  Gardeners'  Chronicled  This  was  a  trans- 
lation of  a  report  made  by  Prillieux,  inspector-general  of  agricul- 
tural education,  to  the  minister  of  agriculture  of  France,  regarding 
the  value  of  a  mixture  of  copper  sulphate  and  lime  against  the 
mildew  of  the  vine.  The  account  contains  a  brief  history  of  the 
work  done  in  the  Medoc,  and  also  mentions  the  names  of  the 
men  who  were  most  prominently  connected  with  it. 

1  Gard.  Chron.  1885,  Nov.  7,  594. 


Spraying  in  England.  55 

The  sulphide  of  potassium  was  at  one  time  very  highly  recom- 
mended in  England.  It  was  first  successfully  applied  by  Ed- 
mund Tonks.1  He  used  one-half  ounce  in  a  pint  of  water,  and 
it  proved  to  be  very  effective  in  controlling  the  mildew  of 
roses.  This  soon  became  one  of  the  best  known  remedies  in 
England,  and  may  have  been  influential  in  delaying  the  adop- 
tion of  French  practices. 

A  note  published  in  1887  2  says  that  "  the  sulphate  of  copper 
is  being  used  largely  in  America  and  France  against  mildew  on 
vines.  It  is  even  suggested  as  a  remedy  for  potato  mildew,  but 
as  this  grows  in  the  interior  of  the  plant  it  is  difficult  to  see  that 
it  can  effect  much  good.  Amongst  several  methods  of  apply- 
ing the  copper  solution,  the  simplest  is  to  dissolve  1  pound  of 
the  pure  sulphate  in  25  gallons  of  water.  Spray  the  vines 
with  a  force-pump  with  a  nozzle  of  fine  aperture.  The  addi- 
tion of  1  pint  of  ammonia  to  the  above  solution  adds  to  the 
effect.  By  ammonia  we  presume  a  solution  of  the  carbonate  is 
intended." 

The  progress  made  in  France  was  carefully  watched  by  some 
of  the  English  journals.  The  results  of  the  more  important 
experiments  ere  published,  and  English  gardeners  were  not 
wanting  in  information  regarding  the  value  of  the  copper  com- 
pounds. A  few  of  the  more  important  articles  may  here  be 
mentioned.  The  Gardeners'  Chronicle  was  especially  active  in  this 
respect,  and  in  1888  3  it  gave  an  account  of  the  method  of  mak- 
ing the  Bordeaux  mixture  as  recommended  by  Prillieux.  Three 
weeks  later  4  it  speaks  of  the  experiments  of  Prillieux  regarding 
the  treatment  of  potatoes  for  the  blight.  These  experiments 
were  very  successful,  and  if  the  methods  had  been  adopted  in 
England  great  losses  would  have  been  prevented.  During 
January  of  the  following  year  5  there  appeared  a  translation  of 
an  article  in  the  Revue  Horticole  regarding  the  proper  manufact- 
ure and  use  of  the  sulphate  of  copper  and  lime  mixture.  Sev- 
eral such  translations  were  made  during  1890,  but  these  were 
apparently  not  heeded  until  1891,6  when  the  Royal  Agricultural 
Society  of  England  conducted  some  experiments  for  the  preven- 
tion of  blight  upon  potatoes.  These  experiments  are  probably 

i  Gard .  Chron.  1885,  Feb.  28,  2T6.  *  Ibid.  Sept.  22,  332. 

» Ibid.  18ST,  Aug.  6,  166.  6  Ibid.  1889.  Jan.  12,  50. 

a  Ibid.  1888,  Sept.  1,  244.  c  Ibid.  1891,  Aug.  1,  13T. 


56  The  Spraying  of  Plants. 

the  first  of  any  importance  which  were  undertaken  in  England, 
yet  they  were  not  begun  until  four  years  after  the  value  of  the 
copper  compounds  had  been  known  there.  Messrs.  Button  and 
Sons  undertook  a  similar  work.  These  first  trials  were  not  so 
successful  as  had  been  hoped,  and  undoubtedly  prevented,  to  a 
certain  extent,  the  more  general  adoption  of  the  remedies. 

The  French  authorities  were  almost  exclusively  quoted  until 
1891.  By  this  time  the  work  in  America  had  assumed  such 
proportions  that  much  information  of  a  very  varied  character 
was  continually  appearing.  This  was  freely  abstracted  by  the 
English  journals,  and  during  1890*  and  1891,  doubts  regarding 
the  value  of  the  copper  compounds  as  fungicides  were  partially 
removed  from  the  minds  of  English  gardeners.  But  faith  came 
slowly.  The  Highland  and  Agricultural  Society  made  ex- 
periments which  were  discouraging  in  their  results,1  and  as  a 
rule  the  first  trials  were  not  followed  by  such  marked  benefits 
as  were  reported  from  continental  Europe.  As  the  methods  of 
making  the  application  improved,  however,  the  growers  became 
encouraged,  and  during  the  last  two  or  three  years  potatoes  have 
been  very  generally  treated  with  copper  compounds  for  the 
blight  by  the  more  progressive  growers.  The  successful  issue 
of  experiments  made  in  the  United  States  has,  no  doubt,  ma- 
terially assisted  in  bringing  about  this  result. 

The  new  insecticides  have  been  adopted  by  English  gardeners 
even  more  slowly  than  were  the  fungicides.  Although  the  value 
of  kerosene  for  the  destruction  of  insect  life  has  long2  been 
known  there,  its  use  is  still  very  limited.  This,  in  all  probabil- 
ity, is  due  to  the  fact  that  the  remedies  already  at  hand  are  so 
effective  that  little  demand  is  felt  for  others,  —  a  condition  of 
affairs  upon  which  English  gardeners  are  to  be  congratulated. 

The  arsenites  also  are  very  rarely  applied,  not  only  in  England 
but  throughout  Europe.  Their  use  is  not  so  imperatively  de- 
manded as  in  America,  and  as  there  is  a  certain  amount  of 
danger  in  having  them  upon  the  premises,  they  have  not  been 
looked  upon  with  favor.  The  use  of  arsenic  for  the  destruc- 
tion of  insects  is  by  no  means  a  novelty  in  England.  Mr. 
Gordon,  the  superintendent  of  the  ornamental  department  of  the 

1  The  Garden,  1892,  Feb.  6,  133,  based  upon  an  article  appearing  in  the 
Morning  Post. 

>  Oard.  Chron.  1882,  July  15,  85.    Also  known  as  Paraffine  in  England. 


Spraying  in  Australasia.  57 

garden  of  the  London  Horticultural  Society,  says  that  "small 
brown  ants  are  also  very  troublesome  [to  orchid  growers],  but 
they  may  be  destroyed  by  placing  sugar  and  arsenic,  ground  to 
an  impalpable  powder,  on  bits  of  card  near  the  places  they  fre- 
quent." 1  A  fear  of  poisoned  fruit  following  the  use  of  arsenic 
has  also  been  expressed,  and  this,  although  perfectly  groundless, 
has  worked  against  the  introduction  of  such  remedies.  But 
nevertheless,  spraying  has  now  become  the  rule  and  not  the 
exception  in  some  parts  of  England.2  This  applies  particu- 
larly to  "  the  various  fruit  farms  around  Evesham  and  Pershore  " 
and  may  also  be  true  of  other  localities.  The  benefits  derived 
from  the  practice  are  being  appreciated,  and  eventually  all 
growers  must  see  the  necessity  of  its  adoption. 

V.   IN  AUSTRALASIA. 

Plants  suffer  from  disease  wherever  they  may  be  grown. 
If  they  are  introduced  into  a  new  locality,  the  old  diseases  fol- 
low them.  Such  has  been  the  case  in  Australia  and  Tasmania. 
These  countries  have  recently  taken  a  prominent  position  as 
producers  of  fine  fruit,  but  here,  as  elsewhere,  the  horticulturist 
must  be  constantly  on  the  alert  to  save  his  crop  from  some  other 
claimant.  The  spray  evidently  did  not  meet  with  much  opposi- 
tion in  those  far-away  lands,  but  it  was  welcomed  as  an  agent 
which  would  assist  in  the  production  of  more  perfect  crops.  As 
early  as  1886,  F.  S.  Crawford3  experimented  with  ferrous  sul- 
phate and  later  he  recommended  its  use  at  the  rate  of  one 
pound  to  ten  gallons.  It  was  only  to  be  applied  to  dormant 
wood.  The  following  compounds  are  also  mentioned,  all  but 
the  first  two  being  quoted  from  American  publications :  car- 
bolic acid  emulsion,  copper  sulphate,  eau  celeste  (Audoynaud 
process),  eau  celeste  (modified  formula),  Bordeaux  mixture, 
sulphatine,  sulphatine  (Davenport's  modification),  and  David's 
powder. 

1  George  Gordon  in  a  paper,  "  Notes  on  the  Proper  Treatment  of  Epiphytal 
Orchids,"  Jour,  of  the  London  Hort.  Soc.  iv.  19,  communicated  in  Nov.  1848. 

*  Jour,  of  the  Royal  Hort.  Soc.  1895,  Jan.  185. 

8  Extract  from  a  paper  by  F.  S.  Crawford,  read  at  the  Congress  of  the  Central 
Bureau  of  Agriculture  of  South  Australia,  held  in  Adelaide,  1S90,  March  4-7.  Cited 
in  Gard.  Chron.  1890,  July  19,  69. 


58  The  Spraying  of  Plants. 

Tasmania  has  been  remarkably  vigorous  in  fighting  insect 
and  fungous  pests,  and  the  government  has  passed  a  law  (52 
Viet.  No.  16)  which  makes  it  a  finable  offense  for  a  grower  to 
neglect  cleaning  his  orchard : 

"  '  The  Colony  of  Tasmania  is  divided  into  thirty  "  fruit  dis- 
tricts "  to  make  better  provision  for  the  destruction  of  the 
codlin-moth.  Every  person  who  sells,  or  offers  for  sale,  any 
fruit  infected  with  the  moth  is  liable  to  a  penalty  of  five 
pounds. 

"  <  Bandages  to  be  placed  upon  the  trunks  of  the  trees  not 
later  than  December  in  each  year. 

" « Farmers  shall  remove  all  rough  and  scaly  bark  from  trees, 
and  burn  or  otherwise  effectually  destroy  such  bark  as  soon  as 
removed.' 

"  Similar  methods  are  in  use  in  Australia.  There  are  persons 
appointed  by  the  Agricultural  Bureau  in  each  district  (I  believe 
there  are  eighty  odd  districts  in  Australia,  and  over  thirty  in 
Tasmania)  to  see  that  the  law  is  not  evaded."  * 

»  Jour,  of  the  Royal  Hort.  Soc.  1895,  Jan.  185. 


CHAPTER  III. 

SPRAYING  IN  AMERICA. 

I.   IN  THE  UNITED  STATES. 

Spraying  for  Leaf-eating  Insects  and  the  Codlin-moth. 

IT  was  not  until  about  1860,  when  a  ravenous  [insect  —  the 
currant  worm  —  had  been  introduced  into  the  Eastern  States, 
and  another  —  the  potato  beetle  —  into  the  Western,  that  Amer- 
ican farmers  fully  realized  the  necessity  of  discovering  some 
materials  which  would  be  more  energetic  in  the  destruction  of 
insect  life  than  any  at  that  time  in  common  use.  Hellebore 
was  only  partially  successful  in  treating  the  currant  worm,  as 
the  fresh  article  could  not  always  be  obtained,  and  it  was  of 
little  value  after  having  been  long  exposed  to  the  air.  The 
insecticidal  value  of  kerosene  had  long  been  known,  but  the 
use  of  the  oil  was  not  understood,  so  that  it  was  only  sparingly 
applied.  In  the  Eastern  States,  therefore,  the  progress  of  the 
currant  worm  was  not  very  seriously  checked,  and  the  majority 
of  the  plants  were  defoliated  year  after  year. 

Since  the  insecticides  then  known  were  of  so  little  value  in 
exterminating  a  soft-bodied,  chewing  insect  like  the  currant 
worm,  how  much  less  would  be  their  effect  upon  such  a  vigor- 
ous and  well-protected  individual  as  the  potato  beetle !  This 
insect,  a  native  of  the  Rocky  Mountains,  began  to  travel  east- 
ward when  potato  culture  had  extended  so  far  to  the  west  that 
the  plant  was  grown  in  the  territory  occupied  by  the  beetle.  It 
then  left  the  plants  upon  which  it  had  been  feeding,  and  at- 
tacked the  potato  vines.  The  march  to  the  east  then  followed. 
In  1859  the  insect  had  "  reached  a  point  one  hundred  miles  to 
the  west  of  Omaha  City,  in  Nebraska."  1  In  1868  it  extended 

»  Biley,  "  Potato  Pests,"  1876, 12. 
59 


60  The  Spraying  of  Plants. 

to  central  Missouri  and  southern  Illinois.  In  July,  1870,  the 
insect  was  found  in  Ontario,  Canada ;  and  in  1872  it  arrived 
in  central  New  York.  Two  years  later,  it  reached  the  Atlantic 
coast,  having  crossed  nearly  two-thirds  of  the  continent  in  the 
short  space  of  fifteen  years. 

The  insects  ate  as  vigorously  as  they  traveled.  Potato 
fields  were  stripped  of  every  vestige  of  foliage;  desolation 
could  everywhere  be  seen ;  and  as  this  increased,  the  yield  of 
tubers  decreased.  At  first,  it  seemed  as  if  nothing  could  stop 
the  ravages  of  the  pest,  and  it  threatened  the  entire  potato 
industry  of  the  country.  All  known  remedies  failed,  and  the 
future  must  have  appeared  dark  to  the  Western  planters,  until 
some  remedy  could  be  found  that  would  destroy  the  beetles, 
and  save  the  foliage  of  the  vines. 

Fortunately,  this  remedy  was  not  long  in  coming ;  but  who 
first  suggested  it,  and  who  first  used  it  for  the  destruction  of 
the  potato  beetle,  will  perhaps  never  be  told.  Paris  green 
appeared  upon  the  scene  sometime  between  1860  and  1870. 
The  use  of  this  deadly  poison  may  have  originated  with  sev- 
eral persons ;  for  some  poison  of  this  natufe~was"evT3ently 
needed  to  destroy  such  a  voracious  feeder.  The  use  of  Paris 
green  as  a  standard  insecticide  undoubtedly  began  in  the 
Western  States,  and  there  the  applications  to  the  vines  were 
considered  as  of  primary  importance  in  securing  a  crop.  The 
use  of  the  poison  was,  to  a  limited  extent,  checked  by  the 
possible  dangers  connected  with  its  careless  handling.  It  is 
also  very  injurious  to  foliage,  when  applied  pure,  especially  in 
large  quantities,  and  this  may  have  exerted  a  certain  influence 
in  preventing  its  general  adoption.  But  the  weight  of  these 
objections  was  soon  overcome  by  the  absolute  necessity  of 
treating  the  vines  in  order  to  save  them. 

In  1868  the  value  of  the  poison  appears  to  have  been  fairly 
well  known,1  one  man  going  so  far  as  to  obtain  a  patent  upon 
a  mixture  of  one  part  Paris  green  and  two  of  mineral  paint.2 

1  American  Entomologist,  1869,  July,  219,  citing  from  the  Galena  (Ills.) 
Gazette.  The  editors  of  the  Am.  Ent.  also  carried  on  experiments  in  1868.  See, 
also,  an  account  of  the  experiments  made  by  Saunders  and  Reed,  in  which  were 
tested  Paris  green,  arsenious  acid,  copper  sulphate,  bichromate  of  potash,  powdered 
hellebore,  carbonate  of  lime,  and  ashes  mixed  with  air-slaked  lime  ;  none  of  these, 
except  Paris  green,  were  found  to  be  of  value.  Canadian  Entomologist,  1871, 
July,  41.  2  Eiley,  U.  &  Ent.  Com.  1880,  Bull.  3,  57. 


Spraying  with  Paris   Green.  61 

In  after  years,  several  other  patents  were  granted  upon  various 
mixtures  in  which  this  poison  held  a  prominent  position.1  The 
arsenite  was  most  generally  applied,  however,  by  being  mixed 
with  flour,  plaster,  or  ashes,  the  proportions  varying  from  two 
to  ten  or  twelve  parts  of  the  diluent  to  one  of  the  poison. 
The  proportion  of  poison  was  greatly  reduced  in  later  years, 
only  one  part  to  twenty-five  or  thirty  being  used. 

Applications  of  Paris  green,  when  mixed  with  water,  do  not 
appear  to  have  been  commonly  made  during  the  first  few  years 
following  the  introduction  of  the  poison.  The  difficulty  of 
transporting  the  water  appears  to  have  been  one  of  the  main 
objections  to  this  method ;  and  another,  perhaps  an  even  more 
serious  one,  was  the  imperfect  distribution  which  resulted  from 
sprinkling  the  plants  with  the  aid  of  only  very  unsatisfactory 
appliances,  watering-cans  or  brooms  being  at  first  used  for  this 
purpose.  It  is  only  since  the  introduction  of  improved  ma- 
chinery that  the  poison  has  been  generally  applied  in  this 
manner. 

The  success  attending  the  use  of  Paris  green  in  the  destruc- 
tion of  the  potato-beetle  soon  suggested  its  application  to  plants 
that  suffered  from  similar  insect  pests.  In  1872  Riley  sug- 
gested the  treatment  of  cotton  plants  with  Paris  green  for 
the  destruction  of  the  cotton  worm.2  It  was  advised  to  use 
from  one-half  to  one  pound  of  the  poison  in  forty  gallons  of 
water,  this  being  considered  as  sufficient  for  a  single  treatment 
of  an  acre.  The  poison  is  still  extensively  used,  although  the 
proportions  of  the  water  and  the  arsenite  have  varied. 

Le  Baron,  in  1872,  made  a  suggestion  which  was  followed 
by  consequences  vastly  more  important  than  were  probably 
dreamed  of  by  its  originator.  The  spring  canker-worm  of  the 
apple  was  doing  much  damage  in  the  West,  and  in  spite  of  the 
many  devices  invented  for  its  capture  or  destruction,  the  pest 
continued  to  spread,  and  serious  losses  were  inflicted.  The 
recommendations  made  by  Le  Baron,3 at  that  time  state  entomol- 
ogist of  Illinois,  were  for  the  growers  to  place  their  main  reli- 
ance upon  measures  which  prevented  the  insect  from  gaining 
a  foothold  in  the  trees.  In  case  such  precautions  should  be 

i  Riley,  U.  S.  Ent.  Com.  1880,  Bull.  3,  5T. 

*  Ibid.  56. 

8  Second  Ann.  Kept,  on  the  Noxious  Insects  of  the  State  of  Illinois,  18T2, 116. 


62  The  Spraying  of  Plants. 

neglected,  however,  he  says  that  "  strong  washes,  such  as  Paris 
green  water,  or  suds  made  from  the  whale-oil  soap,  thrown 
upon  the  trees  with  a  garden  syringe,  will  also  materially  check 
their  depredations."  This  is  the  first  statement  which  I  have 
been  able  to  find  in  which  the  syringing,  or  spraying,  of  apple 
trees  with  Paris  green  is  recommended,  and  it  was  adopted  to  a 
limited  extent  in  Illinois  in  1873. l 

This  note  attracted  but  little  attention  on  the  whole.  It  was 
not  until  four  years  later  that  Cook  advised  the  use  of  Paris 
green  for  the  destruction  of  canker-worms,  and  even  at  that 
date  its  use  was  supposed  to  injure  the  tree  at  certain  times,  and 
the  total  loss  of  fruit  was  not  thought  improbable.2  In  1878 
many  orchardists  in  Michigan  sprayed  their  trees  with  a  mix- 
ture of  Paris  green  and  water,  and  from  that  time  the  use 
of  this  poison  has  been  considered,  in  that  state,  as  the  best 
means  of  destroying  the  pest.3  Eastern  growers,  with  scarcely 
an  exception,  were  slow  to  imitate  the  more  progressive  Western 
pomologists.  As  late  as  1877,  H.  T.  Brooks  still  recommended 
to  the  members  of  the  Western  New  York  Horticultural  So- 
ciety the  use  of  bandages  upon  apple  trees  to  prevent  insects 
from  ascending  the  trunks ;  and  two  years  later  a  member  of 
the  same  society  "had  known  them  [the  cankerworms]  de- 
stroyed by  showering  the  trees  with  a  solution  of  Paris 
green."* 

Paris  green,  or  some  other  form  of  arsenic,  was  nevertheless 
destined  to  play  another  important  part  in  the  destruction  of 
insects  that  were  injurious  to  apples.  The  codlin-moth,  which 
in  the  larval  stage  causes  apples  to  be  "  wormy,"  was  flourishing 
unchecked  upon  this  fruit  throughout  the  Central  and  Eastern 
States.  Several  remedies  were  suggested,  but  none  appeared  to 
possess  much  practical  value.  An  effectual  remedy  was  eventu- 
ally found,  not  by  entomologists,  however,  but  by  practical 
growers.  The  first  statement  that  attracted  attention,  and 
which  was  followed  by  close  investigation,  appears  to  have 
been  made  by  Edward  P.  Haynes,  in  1878.  He  was  then  living 
near  Hess  Road,  Niagara  County,  N.Y.  In  the  spring  of  1878  he 

1  Third  Bept.  U.  S.  Ent.  Com.  1880-82,  192. 

2  Bept.  Mich.  Pom.  Soc.  1876,  43. 
s  Ibid.  18T8,  236. 

*  Chapin,  Bept.  of  West.  HT.  Y.  Hort.  Soc.  1879,  74. 


Paris   G-reen  and  the   Oodlin-moth.  63 

applied  to  J.  S.  Woodward,  of  Lockport,  X.Y.,  for  advice  in 
regard  to  the  best  method  of  treating  the  canker-worms  which 
were  then  ruining  his  apple  trees.  Mr.  Woodward  advised  the 
use  of  Paris  green.  I  will  here  quote  from  a  letter  which  Mr. 
Woodward  was  so  kind  as  to  send  me  in  May,  1894:  "I  ad- 
vised him  to  spray  with  Paris  green,  and  went  with  him  to  get 
the  necessary  apparatus.  He  took  it  home  and  used  it,  and 
when  I  saw  him  again  the  following  fall,  he  told  me  of  its  hav- 
ing not  only  rid  the  orchard  of  canker-worms,  but  that  the 
apples  on  the  sprayed  part  were  much  less  eaten  by  codlin- 
moths.  I  was  so  much  interested  that  I  went  to  see  the  or- 
chard and  was  convinced  that  the  spraying  had  done  what  he 
had  said.  This  fact  I  reported  at  the  following,  January,  meet- 
ing of  our  society  [West.  X.  Y.  Hort.  Soc.]  and  shall  never  for- 
get this  because  of  the  way  in  which  I  was  jumped  upon  as  a 
crank."  J  The  record,  which  may  be  found  in  the  report  of  the 
society,  is  undoubtedly  the  first  that  gives  an  account  of  the 
successful  treatment  of  the  codlin-moth  by  means  of  Paris 
green.  The  same  fact  was  also  mentioned  in  a  meeting  of  the 
Michigan  Pomological  Society  held  in  Hillsdale,  Feb.  11-13, 
1880.2  At  the  annual  meeting  of  this  society,  held  at  Ann  Ar- 
bor, Dec.  6-8,  1880,  Professor  Cook  reported  having  used  the 
remedy  suggested  by  Mr.  Woodward  with  the  following 
result:  "I  thoroughly  sprayed  some  Siberian  crab-apple  trees 
the  25th  of  May,  and  again  the  20th  of  June  ;  but  I  used  Lon- 
don purple,  1  tablespoon  to  2  gallons  of  water.  The  fruit 
of  these  trees  has  been  seriously  injured  whenever  they  have 
borne  during  previous  years.  This  year  they  were  loaded  with 
fruit,  but  careful  examination,  made  Aug.  19th,  discovered  not 

1  Kept,  of  a  meeting  of  the  West.  N.  T.  Hort.  Soc.,  held  in  Rochester,  1879, 
Jan.  22,  23,  20.    It  appears  that  the  same  discovery  was  also  made  at  this  time 
in  Iowa.      According  to  Rural  Life  of  May  30,  1895,  13.  London  purple  was 
used  in  1878  to  destroy  canker-worms,  and  this  is   said  to  have  saved  the  crop 
from  the  codlin-moth :   "  Hon.  John   M.   Dixon,  of  Oskaloosa,  was  then   [1877] 
trustee  of  the  Iowa  Agricultural  College.     He  watched  our  work  and  concluded 
he  would  try  spraying  on  his  big  orchard  to  destroy  the  canker-worm.     In  doing 
this  he  made  a  great  discovery.    The  spraying  was  timely  for  destroying  the 
codlin-moth.     He  marketed,  in  1878,  carloads  of  apples  in  Minneapolis  entirely 
free  from  worms  or  wormholes.     Mr.  Dixon  and  the  writer  [Professor  Budd]  told 
of  these  results  in  the  horticultural  reports  and  the  press,  yet  so  far  as  we  know 
others  have  been  given  the  credit  for  this  pioneer  work." 

2  Bept.  Mich.  Pom.  Soc.  1880,  26. 


64  The  Spraying  of  Plants. 

a  single  injured  apple.  Other  apple  trees,  only  a  few  rods  dis- 
tant, which  were  not  treated  with  the  poisonous  liquid,  are 
bearing  fruit,  one-fourth  to  one-half  of  which  is  'wormy.'"1 
This  is  probably  the  first  experiment  made  by  an  entomologist 
for  the  control  of  the  codlin-moth  by  the  use  of  an  arsenical 
compound.  Still,  scientists  were  slow  to  recommend  the  use 
of  the  poison.  The  year  following,  Cook  said :  "I  have  been 
very  successful  in  the  use  of  Paris  greon,  and  others  have,  and 
for  myself  I  would  not  hesitats  to  use  it,  but  some  of  our  best 
entomologists  consider  there  is  great  danger  in  the  use  of  this 
poison,  and  I  prefer  not  to  be  put  on  record  as  recommending 
it  for  others'  use.  I  used  the  poison  on  my  own  trees,  and  shall 
not  hesitate  to  do  so  ar;r,in."  2  ~7oodward  at  the  same  time 
said  that  the  remedy  was  regularly  used  in  western  New  York, 
where  "  two  men  will  spray  one  hundred  trees  in  half  a  day, 
.  .  .  and  I  have  yet  to  learn  of  a  single  instance  where  any  one 
has  been  injured  by  the  use  of  the  poison." 

Notices  of  this  work  appeared  in  most  of  the  leading  agri- 
cultural papers.  Yet  comparatively  little  was  heard  of  the  use 
of  Paris  green  for  the  destruction  of  the  codlin-moth  during 
the  next  few  years.  Orchardists  seemed  to  hesitate  in  apply- 
ing the  poison  for  this  insect,  although  it  was  quite  freely  used 
for  the  canker-worm.  But  very  few  of  the  most  progressive 
men  adopted  the  method,  with  apparently  satisfactory  results. 
After  the  establishment  of  the  experiment  stations,  in  fulfill- 
ment of  the  requirements  of  the  Hatch  bill  of  1887,  a  new 
impetus  was  given  to  the  adoption  of  the  arsenites.  As  differ- 
ent experimenters  published  the  results  of  their  work,  the  value 
of  the  practice  became  more  generally  known,  and  gradually  an 
ever-increasing  number  of  growers  accepted  the  assistance  of 
the  arsenites  in  the  production  of  perfect  fruit. 

For  several  years  after  the  discovery  of  the  successful  treat- 
ment of  the  canker-worm,  recommendations  regarding  the 
destruction  of  other  foliage-eating  insects  were  more  freely 
made  than  adopted.  In  the  report  of  the  United  States  Depart- 
ment of  Agriculture  for  1878,  C.  V.  Riley  recommended  the 
use  of  Paris  green  for  the  destruction  of  the  following  insects : 
Chapin's  apple-leaf  sewer,  the  thick-thighed  walking  stick,  the 
imported  elm-leaf  beetle,  the  juniper  web-worm,  and  the  apple 

i  Kept.  Mich.  Pom.  Soo.  1880, 136.  »  Ibid.  1881,  130. 


Introduction  of  London  Purple.  65 

coleophora.  The  first  regular  experiment  station  to  publish 
results  of  the  use  of  Paris  green  for  controlling  the  codlin-moth 
was  the  New  York  State  station  ;  1  Goff  had  used  it  the  pre- 
ceding year  also  with  apparently  good  results  against  the 
squash  vine  borer.2  It  was  in  this  and  the  following  decade 
that  Paris  green  and  London  purple  established  themselves 
firmly  as  the  most  valuable  agents  for  the  destruction  of  chew- 
ing insects. 

London  purple  was  early  in  the  field  as  a  rival  of  Paris  green. 
It  is  cheaper  than  the  latter,  contains  large  amounts  of  arsenic, 
and  can  be  more  easily  applied.  But  its  composition  is  not  so 
uniform,  and  it  is  more  apt  to  injure  foliage,  so  that  on  the 
whole  Paris  green  has  been  preferred.  London  purple  was 
manufactured  in  England,  and  I  have  been  fortunate  in  learn- 
ing of  the  manner  in  which  the  poison  was  introduced  into 
this  country.  Dr.  C.  E.  Bessey,  of  Lincoln,  Neb.,  was  the  first 
to  use  it  for  the  destruction  of  the  potato  beetle,  as  a  substitute 
for  Paris  green,  and  his  work  and  that  of  Professor  Budd  of 
Ames,  Iowa,  first  attracted  public  attention  to  the  new  insecti- 
cide. The  name  "London  purple"  was  suggested  by  Dr. 
Bessey  in  1878,  and  he  has  been  so  closely  connected  with  the 
introduction  of  the  poison  that  a  letter  received  from  him 
under  date  of  Feb.  20,  1895,  is  here  published  in  full : 

"  In  my  file  of  letters  I  find  that  on  Sept.  7,  1877,  the  Lon- 
don firm  of  Hemingway  &  Co.,  of  60  Mark  Lane,  wrote  me 
their  first  letter  enclosing  a  small  packet  of  London  purple  (not 
so  named  then)  and  asking  me  to  make  a  trial  of  it,  offering  to 
send  one  or  two  casks  of  the  material  free  of  cost.  My  reply 
was  returned  soon  enough,  so  that  on  Dec.  18,  1877,  they 
wrote  again  as  follows  :  '  In  conformity  with  your  favor  of  the 
22d  October  we  have  done  ourselves  the  pleasure  of  for- 
warding to  your  address  per  steamer  Holland  to  New  York, 
thence  by  express  of  Messrs.  Baldwin  Bros,  of  that  city,  three 
kegs  of  the  substance  for  poisoning  the  Colorado  beetle,  and 
shall  be  much  obliged  by  your  sending  us  as  early  a  report  as 
you  can  of  the  results  of  the  trial  experiments  you  may  make 
with  it.' 

i  Goff,  Ann.  Rept.  N.  Y.  State  Agric.  Exp.  Sta.  1885,  246. 
s  Ibid.  1884,  318. 
F 


66  The  Spraying  of  Plants. 

"  The  bill  of  lading  shows  that  the  kegs  left  New  York  City 
on  Feb.  2,  1878,  but  it  was  near  the  end  of  the  month  when 
they  reached  me  at  Ames,  Iowa. 

"  My  next  letter  from  Hemingway  &  Co.  bears  date  of  March 
19,  1878,  asking  as  to  the  arrival  of  the  kegs.  The  next 
letter  from  the  firm  I  have  temporarily  mislaid,  but  on  July 
26,  1878,  it  wrote  as  follows :  '  We  have  to  thank  you  for 
your  favor  of  the  4th  inst.  and  are  of  course  pleased  to  find  that 
our  expectations  are  correct  as  to  the  poisonous  nature  of  the 
"  London  purple  "  to  the  potato  beetle.  We  anxiously  await 
the  result  of  the  further  experiments  promised  in  yours,  and 
shall  in  the  meantime  have  prepared  some  few  tons  of  the 
material  ready  to  be  sent  over.' 

"  On  Nov.  28,  1878,  it  wrote  as  follows  :  *  We  are  exceedingly 
obliged  for  your  favor  of  the  9th  inst.  and  the  Nos.  3  and  4 
of  your  college  gazette  1  (which  came  by  same  mail)  containing 
yours  and  Professor  Budd's  kind  notice  of  our  new  poison 
(London  purple).  Since  last  we  had  this  pleasure,  we  have 
been  in  correspondence  with  Messrs.  Ward  &  Co.,  to  whom  we 
intend  sending  our  first  consignment,  and  which  we  intend 
shall  leave  hero  immediately.' 

"  My  letter,  in  which  I  suggested  the  name  '  London  purple,' 

1  "A  CHEAP  AND  VALUABLE  POISON  FOB  THE  POTATO  BEETLE.—  Last  winter 
the  College  received,  for  trial,  a  quantity  of  a  material  called  by  the  manufacturers, 
'  London  purple,'  and  designed  to  be  used  for  killing  the  Colorado  potato  beetle 
(the  potato  bugs  of  common  parlance) .  Upon  trial  it  was  found  to  be  valuable, 
killing  the  old  as  well  as  the  young  insects  with  great  certainty.  The  virtue  of  Lon- 
don purple  lies  in  the  arsenic  which  it  contains,  just  as  in  the  case  of  Paris  green. 
There  are,  however,  several  advantages  possessed  by  the  new  poison  over  the  old, 
among  which  are,  first,  its  extreme  fineness,  permitting  it  to  be  mixed  with  water  ; 
second,  its  adhesiveness  ;  when  once  applied  it  adheres  tenaciously  to  the  leaves, — 
this  is  due,  no  doubt,  to  its  finely  divided  condition  ;  third,  its  purple  color  enables 
one  always  to  detect  its  presence  on  leaves,  even  when  it  exists  in  but  very  small 
quantities ;  this  will  not  only  guard  against  accidents,  but  at  the  same  time  be  of 
considerable  account  in  enabling  one  to  always  know  when  it  is  necessary  to  make 
another  application  ;  fourth,  its  cheapness  as  compared  with  Paris  green  ;  it  will  be 
impossible  to  say  just  what  the  cost  per  pound  will  be,  until  a  considerable  quantity 
has  been  brought  into  our  markets ;  it  will,  however,  in  all  probability  not  be  more 
than  one-fourth  that  charged  for  Paris  green.  The  London  manufacturers  are  now 
making  arrangements  for  putting  into  the  market  a  sufficient  quantity  for  use  upon 
the  crop  of  beetles  in  1879.  They  propose  to  designate  some  firm  in  Des  Moines  to 
take  charge  of  the  matter  of  introducing  it.  "When  it  becomes  available  it  will  be 
well  for  our  potato  growers  to  give  London  purple  the  attention  it  deserves." — The 
College  Quarterly,  Iowa  Agric.  College,  Ames,  Iowa,  Vol.  i.  No.  iii.  Sept. 
1878,  49. 


Introduction  of  London  Purple.  67 

was  in  answer  to  theirs  of  March  19,  1878,  so  it  was  written 
sometime  early  in  April." 

In  another  letter,  Dr.  Bessey  has  informed  me  that  during  a 
visit  which  one  of  the  Hemingway  firm  paid  him  in  Iowa,  the 
statement  was  made  that  the  three  kegs  sent  to  Iowa  were  the 
first  sent  to  America ;  and  the  first  small  packet  sent  in  a  letter 
was  one  of  three  which  were  mailed  at  the  same  time,  the  other 
two  packets  being  addressed  to  two  gentlemen  in  the  United 
States.  One  of  these  was  Professor  A.  J.  Cook,  then  of  Lans- 
ing, Mich.  The  name  of  the  other  was  forgotten,  for  no  reply 
had  been  received  from  him.  Professor  Cook's  answer  had 
been  delayed  or  had  proved  unsatisfactory,  for  all  the  kegs  of 
the  first  shipment  went  to  Iowa,  as  above  stated. 

The  United  States  Department  of  Agriculture  has  also  been 
active  in  bringing  London  purple  to  the  attention  of  horticul- 
turists. In  the  annual  report  of  the  Department  for  1878,  page 
144,  is  given  a  chemical  analysis  of  the  poison,  and  its  use 
is  suggested  as  a  substitute  for  Paris  green.  The  first  direct 
recommendation  that  is  found  in  the  government  reports  to 
this  effect  was  made  by  Riley  on  page  248  of  the  same  publi- 
cation. He  advised  the  destruction  of  the  juniper  web-worm 
by  treating  the  parts  infested  with  either  Paris  green  or  London 
purple.  The  same  was  also  made  to  apply  to  the  apple  coleo- 
phora.  Experiments  to  test  the  value  of  London  purple  were 
carried  on  this  year  by  Riley,  and  the  work  was  so  successful 
that  large  quantities  of  the  poison  were  distributed  to  various 
cotton  growers  in  Georgia,  Alabama,  and  Texas,  where  it  was 
to  be  used  in  the  destruction  of  the  cotton  worm,  in  1879.  The 
result  of  these  tests  was  so  satisfactory  that  London  purple 
was  even  more  strongly  recommended  than  Paris  green.  When 
applied  in  a  dry  state,  the  proportions  which  appeared  most 
promising  to  Dr.  Riley  were  one-half  pound  of  the  poison  to 
eighteen  of  the  diluent.  When  used  with  water,  one-half  pound 
of  the  powder  could  be  used  to  advantage  in  about  fifty  gal- 
lons of  water.  During  the  spring  of  the  same  year,  1879,  A.  R. 
Whitney,  of  Franklin  Grove  111.,  "found  it  to  be  a  perfect  an- 
tidote to  the  canker-worms.1  ..." 

During  this  year,  Trelease  conducted  some  experiments  for 
J.  H.  Comstock,  who  at  the  time  was  chief  of  the  Division  of 

1  Kiley,  U.  S.  Ent.  Com.  1880,  Bull.  3,  60,  61. 


68  The  Spraying  of  Plants. 

Entomology,  in  which  London  purple  was  used  in  comparison 
with  several  other  substances.1  In  this  test  Paris  green  proved 
the  most  satisfactory,  then  arsenious  oxide,  while  London  pur- 
ple stood  third  on  the  list.  The  principal  objection  to  the  last 
two  materials  was  that  they  scorched  the  foliage  of  the  cotton 
plants  to  which  they  were  applied.  The  conclusion  was  also 
reached  that  it  is  more  economical  to  apply  the  powders  when 
mixed  with  water  than  in  the  powder  form,  only  about  one-half 
as  much  poison  being  required  by  the  former  method. 

The  value  of  London  purple  as  an  insecticide  was  recognized 
with  surprising  rapidity.  The  experiments  of  Comstock  and  of 
Riley  were  widely  copied,  and  although  there  were  some  seri- 
ous objections  to  the  use  of  this  arseuite,  its  cheapness  and  the 
ease  with  which  it  could  be  applied  were  greatly  in  its  favor. 
Cook  used  it  successfully  in  1879  against  the  codlin-moth,  and 
with  such  recommendations  it  soon  won  public  favor.  The 
principal  objection  to  its  use  was  the  danger  of  scorching  the 
foliage  of  the  plants,  and  this  probably  is  the  main  reason  why 
it  did  not  entirely  supersede  Paris  green.  It  is  also  less  uni- 
form in  its  composition,  which  renders  it  of  uncertain  value. 
Yet  it  was  only  about  three  years  after  its  introduction  that 
the  value  of  London  purple  was  generally  considered  to  be 
nearly  equal  to  that  of  Paris  green,  and  it  is  so  considered 
to-day. 

Spraying  for  the  Curculio. 

No  subject  connected  with  the  spraying  of  plants,  with  per- 
haps the  exception  of  the  best  methods  of  making  the  kerosene 
emulsion,  has  been  the  subject  of  such  heated  controversy  as 
the  spraying  of  stone  fruits  with  arsenites  to  protect  theni 
from  the  curculio.  The  value  of  the  operation  seems  to  have 
been  first  noted  by  G.  M.  Smith,  of  Berlin,  Wis.  In  1870 
Riley  wrote  an  article  on  this  practice  in  which  he  held  it 
up  to  ridicule,8  and  the  subject  was  again  mentioned  by  the 
same  writer  in  an  article  which  states  that  Smith  recommended 
it  "to  the  Saint  Joseph  (Michigan)  Horticultural  Society,  and 
from  that  time  on  [the  poison]  has  been  occasionally  suggested 

» Ann.  Rtpt.  T.  &  Com.  tfAffHc.  1879,  809. 

*  Third  Kept.  State  Entomoioffist  of  Jfi**wrt,  18. 


Spraying  for  the   Curculio.  69 

in  the  newspapers."1  The  use  of  the  remedy  by  J.  Luther 
Bowers,  of  Herndon,  Va.,  in  1880,  and  by  William  Creed,  of 
Rochester,  N.Y.,  in  1884,  is  also  mentioned.  In  this  report 
the  statement  is  made,  on  page  70,  that  "  Riley,  in  an  address 
delivered  before  the  Mississippi  Valley  Horticultural  Society, 
in  the  early  spring  of  1885,  at  New  Orleans,  in  giving  his 
experience  as  to  the  feeding  habits  of  the  beetle,  urged  experi- 
mentation with  the  arsenicals  in  this  direction  as  promising 
fair  results,"  but  I  have  been  unable  to  find  such  an  expression 
in  the  record  of  the  above  meeting.  In  1885,  Forbes,  of 
Illinois,  applied  Paris  green  for  the  control  of  the  codlin-moth, 
and  at  the  same  time  noted  the  severity  of  injuries  caused  by 
the  curculio  upon  the  apples.  These  experiments  are  reported 
by  Howard,2  and  in  one  of  the  conclusions  he  says :  "  Treat- 
ment with  Paris  green  had  saved  something  more  than  two- 
thirds  of  the  apples  which  would  otherwise  have  been  damaged 
by  the  codliu-moth,  and  something  more  than  one-half  of 
those  which  would  have  been  sacrificed  to  the  curculio." 

In  1887  the  arsenites  appear  to  have  been  tested  for  the  first 
time  in  the  destruction  of  the  plum  curculio  by  an  investigator 
of  recognized  ability.  Cook  made  some  experiments  which  did 
not,  however,  form  a  very  firm  basis  for  the  drawing  of  con- 
clusions. Four  plum  trees  were  thoroughly  sprayed  with  Paris 
green  on  May  18,  the  poison  being  used  at  the  rate  of  one 
tablespoonful  to  six  gallons  of  water.  Unfortunately  no  trees 
of  any  of  the  varieties  sprayed  appear  to  have  been  left  for 
comparison,  and  the  fruit  of  different  trees  was  injured  by  the 
insect  to  a  very  unequal  extent.  The  two  Wild  Goose  trees 
dropped  all  their  fruit.  A  yellow  variety  was  loaded  with  fruit 
of  which  only  15  per  cent  was  affected  while  the  fourth  tree, 
a  purple  variety,  "had  not  less  than  75  per  cent  of  its  fruit 
badly  stung."  8 

During  the  same  year,  W.  B.  Alwood  carried  on  some  limited 
experiments  at  the  Ohio  experiment  station  for  the  destruction 
of  the  plum  curculio,  using  a  Paris  green  spray.  His  conclusion 
was :  "  I  am  confident  the  curculios  eat  enough  to  make  it  pos- 

*  Ann.  Rept.  U.  S.  Com.  of  Agric.  1888,  69.  *  Ibid.  1887, 105. 

8  Rept.  Mich.  Bd.  Agric.  18S7,  40.  See  also  Ibid.  18S6, 141,  where  the  same 
writer  expresses  little  hopes  for  the  success  of  the  arseiiites  in  the  destruction  of 
the  plum  curculio  ;  and  Saunders  in  Rept.  Fruit  Growers'  Ass'n  of  Ont.  1887,  58. 


70  The  Spraying  of  Plants. 

sible  to  poison  some  of  them,  but  the  benefit  to  be  derived  from 
such  is  as  yet  unsettled."1 

In  1888  Weed  made  the  first  report  of  an  experiment  planned 
upon  a  large  scale,  in  which  the  method  could  be  apparently 
well  tested.2  London  purple,  used  at  the  rate  of  one-half  pound 
to  fifty  gallons  of  water,  was  applied  to  seventy-five  Early  Rich- 
mond cherry  trees.  Three  applications  were  made.  As  a  re- 
sult, "  it  was  found  that  14.5  per  cent  of  the  unsprayed  fruit 
gave  evidence  of  curculio  attack,  while  3.5  per  cent  of  the 
sprayed  fruit  was  injured.  There  was  consequently  a  percen- 
tage of  benefit  of  75.8."  The  same  year  similar  experiments 
were  made  upon  plums  and  pears,  but,  as  stated  in  the  record 
{Seventh  Ann.  Rept.  Ohio  Agric.  Exp.  Sta.  134-150),  the  oppor- 
tunities for  a  satisfactory  test  were  not  so  good  as  with  the 
cherries,  so  that  although  the  fruit  was  saved,  less  stress  was 
laid  upon  the  result.8 

Professor  Herbert  Osborn,  of  Iowa,  also  tried  to  solve  the 
problem  during  this  year.  There  was  a  trifling  difference  be- 
tween the  sprayed  and  unsprayed  plots  in  favor  of  the  former, 
but  it  seems  that  two  species  of  insects  were  at  work,  so  that  no 
definite  couclusions  can  be  drawn  regarding  the  value  of  the 
treatment  against  the  plum  curculio  alone.4 

The  experiments  made  by  Professor  Cook  during  1888  were 
somewhat  more  extended  than  those  of  preceding  years,  but 
still  rather  limited.  The  trees,  cherries  and  plums,  were 
sprayed  three  times,  June  6, 12,  and  20,  and  the  results  obtained 
appeared  to  warrant  the  following  conclusions :  "  From  these 
experiments,  and  those  of  former  years,  I  conclude  that  while 
one  application  will  not  save  our  plums  and  cherries,  and  pre- 
vent apples  from  being  stung,  two  or  three  applications  may  be 
of  signal  advantage.5 

In  1889,  Cook  repeated  his  former  experiments.  At  the 
close  of  the  work  his  opinion  was  decidedly  against  the  appli- 
cation of  arsenites.  He  says:  "All  the  trees  were  severely 
attacked  and  all  the  plums  were  lost.  .  .  .  The  arsenites  will 

1  Ann.  Rept.  U.  8.  Com.  of  Agric.  1888,  70.  This  is  the  first  published  state 
ment  of  his  work. 

3  Ohio  Agric.  Exp.  Sta.  Bull.  4,  second  series,  39. 
»  Weed,  American  Naturalist,  1891,  Jan.  70. 

*  Ann.  Rept.  U.  S.  Com.  of  Agric.  1888,  72-75. 

•  Mich.  Agric.  Exp.  Sta.  Bull.  39,  9. 


Spraying  for  the  Curculio.  71 

protect  against  the  plum  curculio  if  they  can  be  kept  on  the 
tree  or  fruit.  But  in  case  of  frequent  rains,  the  jarring  method 
will  not  only  be  cheaper  but  much  more  effective."  1 

Professor  C.  P.  Gillette  experimented  this  year  apparently  in 
the  same  orchard  formerly  used  by  Osborn.  Although  the  cur- 
culio did  but  little  injury,  still  "  the  indicated  saving  of  fruit 
that  would  have  been  injured  in  the  absence  of  treatment  was 
44  per  cent."2  In  a  report  of  the  work,  attention  was  called 
to  the  fact  that  reliable  results  cannot  be  obtained  unless  solid 
blocks  of  trees  are  treated. 

The  work  done  by  Weed  is  by  far  the  most  valuable  and 
convincing  of  the  year.  A  condensed  account  of  his  operations 
during  1889  as  well  as  1890  is  as  follows  : 3 

"  In  1889  the  cherry  experiment  was  duplicated,  the  parts  of 
the  orchard  being  reversed  to  eliminate  any  possible  effect  upon 
the  results  that  might  be  due  to  the  situation.  In  1888  the 
west  half  was  sprayed,  and  the  east  half  left  as  a  check ;  in  1889 
the  east  half  was  sprayed,  and  the  west  left  as  a  check.  London 
purple  was  applied  three  times,  in  the  proportion  of  one  pound 
to  160  gallons  of  water.  At  time  of  ripening,  1000  cherries 
were  picked  from  each  of  twenty-four  trees  in  each  half  of  the 
orchard  —  a  total  of  48,000  cherries  —  and  examined  for  cur- 
culio  injuries.  The  percentage  of  injury  on  the  untreated  trees 
was  6.17,  while  on  the  treated  trees  it  was  1.5.  This  gives  a 
percentage  of  benefit  of  75.6,  —  just  .2  per  cent  less  than  in 
1888.  Plums  sprayed  with  a  combination  of  London  purple 
and  the  Bordeaux  mixture  matured  a  full  crop,  while  unsprayed 
trees  a  few  rods  distant  lost  all  their  fruit.  The  record  of  this 
years'  work  will  be  found  in  the  bulletin  of  the  Ohio  agricul- 
tural experiment  station  for  September,  1889  (Vol.  ii.  133-143). 

"  While  these  experiments  were  made  as  complete  and  satis- 
factory as  circumstances  would  permit,  and  every  essential  de- 
tail was  inserted  in  the  records,  they  were  open  to  three  objec- 
tions, namely  :  First,  that  while  the  remedy  might  work  in  a 
region  like  central  Ohio,  where  fruit-growing  forms  only  a 
small  proportion  of  the  agricultural  interests  of  the  inhabitants, 

1  Proe.  Tenth  Meeting  Soe.  Prom.  Agric.  Science,  1889,  28.  Cited  by  Weed 
in  American  Naturalist.  1891,  Jan.  67. 

*  Iowa  Agric.  Exp.  Sta.,  1890,  May,  Bull.  9,  386. 
8  American  Naturalist,  1891,  Jan.  70-72. 


72  The  Spraying  of  Plants. 

and  where  the  curculio,  though  abundant,  is  not  so  overwhelm- 
ingly present  as  in  a  region  almost  exclusively  devoted  to  fruit 
production,  it  might  be  impracticable  in  the  latter  region ;  sec- 
ond, that  the  plum  orchard  was  not  sufficiently  large  to  make  a 
test  under  the  conditions  of  the  commercial  orchardist ;  and  third, 
that  the  cherries  upon  which  some  of  these  experiments  were 
conducted  ripened  before  the  season  of  egg  deposition  of  the 
curculio  was  over.  The  force  of  these  objections  was  fully 
appreciated  while  the  experiments  were  in  progress,  but  the 
work  was  done  in  the  belief  that  results  of  value  could  be  so 
obtained,  and  with  the  expectation  of  giving  the  method  a 
thorough  trial,  from  the  standpoint  of  the  commercial  orchard- 
ist, if  the  preliminary  tests  were  sufficiently  encouraging. 

"  The  present  season  [1890]  a  plum  orchard  of  900  bearing 
trees  in  Ottawa  County,  Ohio,  right  in  the  heart  of  a  great  fruit- 
growing region,  was  selected  for  the  experiment.  In  the  north 
half  of  it  the  method  of  catching  the  curculios  by  jarring  on  a 
sort  of  inverted  umbrella  mounted  on  wheels  was  employed,  while 
the  south  half  was  sprayed  four  times  with  pure  Paris  green 
mixed  wTith  water,  in  the  proportion  of  4  ounces  to  50  gallons. 

"  The  first  application  was  made  May  8,  just  after  the  blos- 
soms had  fallen  from  the  late-blooming  varieties.  There  was  a 
heavy  rain  the  same  night,  and  it  rained  almost  continuously 
until  May  15,  when  there  was  a  short  cessation.  The  second 
spraying  was  done  on  that  day.  The  third  spraying  was  made 
May  26,  and  the  fourth  and  last,  June  2. 

"  On  the  jarred  portion  of  the  orchard  a  great  many  curculios 
were  caught,  showing  that  they  were  present  in  numbers.  A 
careful  examination  of  both  parts  of  the  orchard  was  made  on 
June  3.  Between  one  and  two  per  cent  of  the  fruit  on  the 
sprayed  trees  had  been  stung,  while  about  three  per  cent  of 
plums  on  the  jarred  trees  were  injured.  No  damage  to  the 
the  trees  was  then  perceptible. 

"  Early  in  July  the  orchard  was  again  examined.  Some  of 
the  sprayed  trees  showed  that  the  foliage  had  been  damaged  by 
the  spraying,  but  the  injury  was  not  very  serious.  Not  over  three 
per  cent  of  sprayed  fruit  was  stung  at  that  time,  while  about 
four  per  cent  of  that  on  the  jarred  trees  were  injured.  But  on 
both  the  fruit  was  so  thick  that  artificial  thinning  was  neces- 
sary to  prevent  overbearing. 


Spraying  for  the  Curculio.  73 

"  A  large  crop  of  fruit  was  ripened  on  both  parts  of  the  or- 
chard, and  so  far  as  could  be  judged  from  one  field  experiment, 
it  showed  that  spraying  is  as  effective  as  jarring."  1 

The  above  experiments  are  the  most  exhaustive  yet  made, 
and  they  seem  to  indicate  that  spraying  for  curculio  is  prac- 
ticable on  a  commercial  scale.  They  are  all  founded  upon 
the  fact  that  the  curculio  does  eat,  a  question  which  has  been 
decided  in  the  affirmative  by  several  entomologists  of  undoubted 
authority.  But  it  still  remains  to  be  determined  how  ex- 
tensively the  beetles  feed  before  the  eggs  are  laid,  and  if  the 
character  of  the  season  may  not  to  a  certain  extent  modify 
the  results  obtained  by  the  use  of  the  arsenites.  In  Xew  York  the 
practice  is  not  regarded  as  being  so  efficient  as  spraying  against 
the  codlin-moth  is,  and  the  older  method  of  jarring  the  trees 
is  still  considered  to  be  the  safest.  S.  D.  Willard  of  Geneva, 
N.Y.,  who  grows  many  plums  and  is  in  a  position  to  be  well 
informed  regarding  the  practices  followed,  writes  me  that  "  the 
majority  of  plum  growers  in  this  State  are  jarring  their  trees 
instead  of  using  any  of  the  arsenical  preparations  to  prevent 
the  working  of  the  curculio."  He  uses  the  jarring  method 
entirely,  in  his  orchards,  and  in  the  spring  of  1895  apparently 
saved  his  crop  by  jarring  the  trees  twice  a  day,  when  spraying 
with  arsenites  utterly  failed. 

Professor  W.  J.  Green,  of  the  Ohio  experiment  station,  has 
been  so  kind  as  to  inform  me  in  regard  to  the  attitude  of 
the  plum  growers  of  that  State  towards  the  use  of  arsenical 
sprays :  "  I  must  say  that  opinions  are  divided  on  the  subject. 
The  majority  of  those  who  have  tried  the  method  [spraying 
with  arsenites]  on  plum  trees  which  were  surrounded  with  other 
kinds  of  fruit  trees  have  failed,  either  wholly  or  partially.  This 
might  be  expected.  ...  On  the  other  hand,  those  who  have 
sprayed  orchards,  leaving  no  trees,  and  doing  the  work 
thoroughly,  have  generally  been  successful  in  saving  the  crops. 
William  Miller,  Gypsum,  Ohio,  and  T.  S.  Johnson,  Port 
Clinton,  Ohio,  will  corroborate  this,  and  I  can  name  others 
near  them  who  have  practiced  the  method  several  seasons,  and 
expect  to  continue.  In  my  experience  the  curculio  is  more  easily 
controlled  with  the  arsenites  than  the  appleworm,  but  only  in 

1  This  experiment  is  recorded  in  Ohio  Agric.  Exp.  Sta.  Bull.  8,  Vol.  iii.  Sept 
1890,  225-228. 


74  The  Spraying  of  Plants. 

orchards  where  all  the  trees  are  sprayed.  In  practice  we  use 
Paris  green  with  Bordeaux  mixture  to  prevent  injury  to  the 
foliage.  We  must  use  the  latter  to  keep  the  leaves  from  drop- 
ping prematurely.  Some  jar  the  trees  occasionally  in  addition  to 
spraying,  in  order  to  gather  and  burn  all  of  the  plums  which 
are  stung.  If  it  were  not  for  the  Bordeaux  mixture  I  think 
that  only  few  would  spray  for  the  curculio,  but  as  it  is  I  think 
that  the  majority  of  orchardists  prefer  spraying  to  jarring !  " 

The  question  is  evidently  not  yet  fully  settled,  but  apparently 
much  seems  to  depend  upon  the  locality,  and  the  time  and 
thoroughness  with  which  the  applications  are  made.1 

Other  Arsenites  than  Paris  Green  and  London  Purple. 

Paris  purple,  another  arsenical  poison,  has  been  on  the 
market  to  a  limited  extent  since  1882  or  1883.  Mr.  A.  Poirrier, 
president  of  the  St.  Denis  Dyestuff  and  Chemical  Co.  of  Paris, 
France,  was  the  introducer  of  this  material.  The  New  York 
agents  of  the  firm,  Sykes  &  Street,  85  Water  Street,  write  me  that 
it  is  the  refuse  obtained  from  the  manufacture  of  magenta,  or 
violet,  or  both.  The  Paris  firm  has  apparently  given  up  the 
manufacture  of  the  product,  and  the  stock  in  this  country  is  now 
very  limited.  It  is  used  in  the  same  way  as  London  purple, 
lime  being  added  to  prevent  injury  to  foliage,  but  larger 
amounts  of  it  appear  to  be  required  to  give  satisfactory  results. 

English  purple  poison,  as  I  am  informed  by  the  introducer, 
Henry  S.  Ziegler,  400  N.  3d  Street,  Philadelphia,  Pa.,  has 
been  upon  the  market  only  a  few  years.  He  states  that  "  the 
name  is  original  with  me,  and  the  composition  consists  of  arse- 
nious  acid  with  an  aniline  base."  It  seems,  therefore,  that  the 
last  three  poisons  mentioned,  London  purple,  Paris  purple,  and 
English  purple  poison,  are  derived  from  the  same  source, 
although  there  are  undoubtedly  certain  variations  in  their 
texture  and  composition.  (For  analyses  see  page  123.)  Con- 
siderable quantities  of  soluble  arsenic  are  present  in  English 
purple  poison,  so  it  should  be  used  with  lime  to  prevent  injury 

1  Much  information  on  this  subject  may  be  found  in  the  following  places : 
Ohio  Agric.  Exp.  Sta.  Vol.  iii.  second  series,  1890,  Bull.  8 ;  Ibid.  Vol.  iv.  second 
series,  Bull.  2 ;  Minn.  Agric.  Ewp.  Sta.  1890,  Bull.  10,  71 ;  Texas  Agric. 
Exp.  Sta.  1894,  Bull.  32,  494  ;  Bailey,  Annals  Hort.  1889,  63. 


Other  Arsenites.  75 

to  foliage.  The  insecticidal  action  of  the  poison  is  not  so 
energetic  as  that  of  Paris  green,  but  if  used  more  freely  the 
insects  will  succumb.  As  yet  English  purple  poison  is  little 
used. 

White  arsenic  has  long  been  known  as  an  effectual  destroyer 
of  insect  life.  In  1848  George  Gordon l  said  that  small  brown 
ants  are  easily  destroyed  by  mixing  with  one  pound  of  loaf 
sugar  a  small  portion  of  arsenic.  Grind  very  fine  and  put  the 
mixture  on  bits  of  white  cards  near  the  places  they  frequent.  It 
is  difficult  to  say  how  generally  this  advice  was  followed,  but  that 
the  poison  was  frequently  tried  for  a  similar  purpose  appears 
very  probable.  Its  very  energetic  poisonous  qualities  when  it  was 
taken  internally  were  well  known,  and  these  must  naturally  have 
occurred  to  the  minds  of  persons  desirous  of  destroying  insect 
as  well  as  animal  life.  Nevertheless,  white  arsenic  was  rarely 
recommended  as  being  a  suitable  poison  to  apply  to  the  foliage 
of  plants,  for  its  action  is  so  caustic  that  the  leaves  are  exposed 
to  nearly  as  great  injury  from  the  remedy  as  from  the  insect  to 
be  overcome.  It  was  used  upon  potato  foliage  for  the  destruc- 
tion of  the  beetle,  but  with  unsatisfactory  results,  Paris  green 
at  the  same  time  proving  so  much  superior  that  the  white 
arsenic  was  abandoned.2  But  an  account  of  the  successful  use 
of  the  poison  against  the  canker-worm  appeared  in  187 1.3  John 
Smith,  of  Des  Moines,  Iowa,  writing  to  the  Western  Pomologist, 
says  that  in  1868  he  used  arsenic,  hellebore,  and  strychnine 
against  the  canker-worm.  He  applied  them  separately  to  dif- 
ferent apple  trees,  using  them  as  follows  : 

Arsenic  one-half  pound  dissolved  in  fifty  gallons  of  water,  and 
applied  to  ten  large  trees. 

Hellebore  two  pounds  mixed  in  four  gallons  of  water,  and 
applied  as  above  in  fifty  gallons  of  water. 

Strychnine  one  bottle,  with  an  amount  of  water  equal  to  that 
used  with  the  other  materials,  and  similarly  applied. 

In  two  days  the  worms  on  the  part  treated  with  the  arsenic 
were  all  dead,  and  the  application  of  hellebore  was  also  followed 
by  good  results.  Strychnine  apparently  possessed  little  value  for 

1  Jour.  London  Rort.  Soc.  1848,  Vol.  iv.  19. 

2  Saunders  and  Eeed,  Canadian  Entomologist,  1871,  July,  41. 

»  Smith,  Western  Pomologist,  Vol.  ii.  1871,  May,  125.  "  See,  also,  The  Smatt 
Fruit  Recorder,  1871,  July  1,  103. 


76  The  Spraying  of  Plants. 

this  purpose.  In  spite  of  this  favorable  report  the  poison  was 
not  in  demand,  because  of  its  caustic  properties. 

After  the  Paris  green  and  London  purple  had  become  well 
known  they  were  both  considered  safer  insecticides  than  white 
arsenic,  and  the  first  was  acknowledged  to  be  the  best  of  the 
three.  Kiley,  however,  did  not  entirely  accept  this  opinion,  but 
thought  that  London  purple  is  not  more  injurious  upon  cotton 
foliage  than  Paris  green  is.1  Cook  was  the  first  to  make  a  care- 
ful study  of  this  point.2  He  made  applications  to  the  foliage 
of  plum,  cherry,  apple,  pear,  peach,  willow,  elm,  and  maple  trees, 
to  determine  the  comparative  degree  in  which  the  three  arsen- 
ites  mentioned  above  are  injurious.  His  first  conclusion  is  as 
follows  :  "  London  purple  is  more  injurious  to  the  foliage  than 
is  Paris  green ;  and  white  arsenic  —  arsenious  acid  —  is  more 
harmful  than  is  either  London  purple  or  Paris  green."  Later 
experiments  have  confirmed  this  result,  and  the  truth  of  its 
general  application  is  accepted. 

The  milk  of  lime  was  first  used  in  connection  with  the  arsen- 
ites  to  overcome  their  caustic  properties,  by  Gillette,  in  the  fall 
of  1889. 8  The  results  were  so  encouraging  that  extensive  ex- 
periments were  carried  on  the  following  year,  and  many  valu- 
able conclusions  were  reached  in  consequence  of  the  careful  and 
extended  observations  made  during  that  season.  It  was  plainly 
shown  that  "  lime  added  to  London  purple  or  Paris  green  in 
water  greatly  lessens  the  injury  that  these  poisons  would  other- 
wise do  to  the  foliage."  4  Another  interesting  result  obtained 
in  these  experiments  was  that  "  lime  added  to  a  mixture  of 
white  arsenic  in  water  will  greatly  increase  the  injury  that  this 
poison  would  otherwise  do  to  foliage.  If  the  arsenic  is  all  in 
solution,  the  lime  will  then  lessen  the  injury,  as  in  the  case  of 
London  purple  and  Paris  green." 

The  next  step  in  this  series  of  advancements  was  taken  by 
Kilgore.6  During  1890  his  investigations  were  made  in  lines 
almost  identical  with  those  followed  by  Gillette,  and  many  of 
the  latter's  conclusions  were  verified.  In  addition  to  these, 


1  Eiley,  If.  S.  Ent.  Com.  1880,  Bull.  3,  62. 

2  Mich.  Agric.  Exp.  Sta.  1889,  Aug.  Bull.  53. 

8  Iowa  Agric.  Exp.  Sta,  1890,  Aug.  Bull.  10,  410. 

« IMd.  419,  420. 

*^.  C.  Agric.  Exp.  Sta.  1891,  July,  Bull.  77  b,  7. 


White  Arsenic.  77 

he  also  gave  directions  for  the  manufacture  of  an  insecticide, 
in  which  white  arsenic  entered  as  one  of  the  principal  ingredi- 
ents. It  was  made  "by  boiling  together  for  one-half  h*our 
in  two  to  five  gallons  of  water 

White  arsenic 1  pound, 

Lime 2  pounds, 

and  dilute  to  required  volume,  say  one  hundred  gallons.  ...  It 
is  desirable  that  the  lime  should  be  present  in  the  boiling  solu- 
tion of  white  arsenic,  since  it  renders  the  latter  insoluble  as  fast 
as  it  goes  into  solution,  thus  reducing  the  volume  of  Water  and 
shortening  the  time  for  obtaining  the  arsenite." 

Two  other  compounds  of  arsenic  have  been  used  for  the  de- 
struction of  insects,  the  first  trial  being  made  upon  the  Gipsy 
moth,  in  Massachusetts.1  One  of  these,  the  arsenate  of  soda, 
"  has  been  recommended  by  various  parties  as  an  insecticide," 
but  the  results  of  the  experiments  show  that  it  injures  foliage 
before  an  efficient  quantity  for  the  destruction  of  the  cater- 
pillars can  be  applied.  The  other,  however,  the  arsenate  of  lead, 
is  promising.  It  was  proposed  as  an  insecticide  in  1892,  by 
F.  C.  Moulton,  a  chemist  in  the  employ  of  the  Gipsy  Moth 
Commission.  It  was  first  tested  against  tent  caterpillars  in 
1893,  with  the  following  results : 2  "  The  smaller  proportions, 
as  |  pound  or  less  to  150  gallons  of  water,  do  not  kill  the  cater- 
pillars \_Clisiocampa  Americana~\  as  quickly  as  is  desirable.  .  .  . 
The  larger  proportions  seem  unnecessary  and  would,  of  course, 
be  rather  expensive  for  general  field  work,  but  some  such  pro- 
portions as  1,  1^,  or  2  pounds  to  150  gallons  of  water  would 
prove  entirely  satisfactory  so  far  as  we  can  judge  from  these 
experiments."  When  used  as  strong  as  2-i  pounds  in  150  gal- 
lons of  water,  no  injury  to  apple  foliage  resulted,  which  is 
indeed  remarkable  when  the  small  amount  necessary  to  destroy 
the  insects  is  considered. 

Caustic  and  Non-poisonous  Insecticides. 

Having  thus  traced  the  introduction  of  the  various  compounds 
of  arsenic,  and  their  gradual  adoption  by  agriculturists  for  the 
destruction  of  chewing  insects,  there  still  remains  the  consider- 

1  Fernald,  Jfass,  Hatch  Agric.  Ewp.  Sta.  1894,  April,  Bull.  24.        »  Ibid.  5. 


78  The  Spraying  of  Plants. 

ation  of  insecticides  which  destroy  the  organism,  not  by  enter- 
ing its  body  with  the  food,  but  by  penetrating  the  outer  cover- 
ings directly,  and  causing  the  death  of  the  insect  only  after  the 
material  has  come  in  contact  with  some  vital  part.  There  are 
several  materials  which  possess  this  power,  and  some  of  them 
have  long  been  in  use.  Strong  alkalies,  such  as  potash  or  soda, 
were  among  the  first  substances  employed  for  this  purpose. 
The  insectidal  value  of  soap  is  largely  due  to  alkalies  which 
have  commonly  been  applied  in  this  form.  The  intrinsic  value 
of  all  soaps  has  caused  them  to  be  used  as  the  foundation 
for  many  mixtures.  Quassia  wood  contains  an  alkaloid  which 
is  fatal  to  insect  life,  and  decoctions  of  the  "  chips  "  have  been 
recommended  since  the  early  part  of  this  century.  Pyrethrum, 
kerosene,  and  resin  can  also  be  added  to  the  list,  although 
their  value  has  not  been  known,  in  all  cases,  so  long  as  that 
of  the  materials  mentioned  above. 

Pyrethrum  first  attracted  the  attention  of  Europeans  early  in 
this  century.1  It  had  long  been  sold  by  the  people  living  south 
of  the  Caucasus  Mountains  in  southeastern  Asia,  the  plant 
being  a  native  of  the  district.  An  Armenian  named  Jumtikoff 
learned  that  the  powder  was  obtained  from  the  flower  heads  of 
certain  species  of  pyrethrum,  and  in  1828  his  son  began  to 
manufacture  the  powder  on  a  larger  scale.  It  was  exported, 
and  at  present  this  industry  brings  large  revenues  into  the 
countries  in  which  it  is  carried  on.  The  species  which  furnishes 
the  best  powder  is  Pyrethrum  roseum  (properly  Chrysanthemum 
cocclneuin)  ;  it  is  not  cultivated  in  Asia,  but  the  flowers  of  the 
wild  plants  are  gathered.  The  Dalmatian  powder  is  produced 
from  Pyrethrum  (or  Chrysanthemum)  cineraricefolium,  a  closely 
related  species.  About  1850,  pyrethrum  powder  was  introduced 
into  France  for  the  destruction  of  insects  in  houses.  In  1856 
good  seeds  were  obtained  from  the  Caucasus,  and  these  having 
been  planted,  a  crop  of  home-grown  seed  was  secured  two 
years  later.  Plants  of  Pyrethrum  roseum  were  grown  in 
America  as  an  ornamental  plant  at  least  as  early  as  1870  ; 
but  the  Dalmatian  form  has  been  grown  for  the  purpose  of 
producing  the  highly  prized  powder.  The  first  to  engage  in 

1  See  TT.  S.  Patent  Office  Kept.  Agric.  185T,  129 ;  Ibid.  1861,  223 ;  and  Ann, 
Kept,  U.S.  Com.  of  Agric.  1881-82,  T6. 


Pyrethrum.  79 

this  industry  was  G.  N.  Milco,  a  native  of  Dalruatia,  who 
successfully  cultivated  Pyrethrum  cineraricefolium  near  Stock- 
ton, Cal.  The  powder  which  he  made  has  been  sold  under 
the  name  "  Buhach."  It  is  in  every  respect  apparently  as 
good  as  the  imported  article,  and  is  even  superior  to  the  latter  in 
regard  to  strength.  It  is  probably  the  best  form  to  use  in  this 
country.  Plants  of  both  species  were  grown  in  Washington, 
D.C.,  in  1881,  with  satisfactory  results.  In  the  spring  of  that 
year  Riley  distributed  seeds  of  the  two  forms  to  growers  in 
various  parts  of  the  country.  In  this  way  the  plants  have 
become  fairly  well  known,  and  the  use  of  the  powder  has  rapidly 
increased.  On  account  of  the  cost,  it  has  been  used  principally 
in  dwellings  and  in  greenhouses.  It  is  most  frequently  applied 
in  the  dry  form,  but  during  the  past  few  years  it  has  given 
good  results  either  when  mixed  with  water,  or  when  the  essen- 
tial oil  has  been  applied  after  being  extracted  by  alcohol ;  an 
infusion  of  the  entire  flowers  is  also  effective. 

It  is  difficult  to  say  when  kerosene  oil  began  to  be  valued 
for  the  destruction  of  insects.  The  oil  was  undoubtedly  used 
before  any  records  of  its  insecticidal  value  were  published ; 
and  one  might  suppose,  from  its  nature,  that  it  would  possess 
energetic  properties  of  this  character.  Turpentine  mixed  with 
earth  and  water  was  successfully  used  to  destroy  worms  on  trees 
as  early  as  1835,1  and  it  is  but  a  step  to  pass  from  this  liquid  to 
the  use  of  kerosene.  The  latter  was  recommended  for  the  de- 
struction of  scale  on  orange  trees  in  1865,2  and  was  also 
successfully  applied  to  oleander,  sago-palm,  acacia,  and  lemon 
trees.  The  oil  was  poured  into  a  saucer  and  applied  by  means 
of  a  feather.  In  June  of  the  following  year,  the  Gardener's 
Monthly  recommended  this  oil  for  destroying  all  insect  life ;  but 
in  an  issue  of  the  next  month,  the  statement  was  modified  by 
saying  that  the  vegetable  oils  were  safer.8  Many  others  proba- 
bly had  the  same  experience,  for  if  not  applied  very  carefully, 
much  injury  to  the  foliage  may  result.  It  has  been  the  practice, 
both  in  Europe  and  this  country,  to  apply  kerosene  with  a 
certain  amount  of  water,  having  one  part  of  oil  to  twenty-five 

1  The  Cultivator,  1S35,  176,  cites  M.  D.  Thosse  in  Sittiman's  Journal. 
*  Gardener's  Monthly,  1865,  Dec.  364. 
»  Ibid.  1866,  June,  176,  and  July,  208. 


80  The  Spraying  of  Plants. 

of  water,  more  or  less.  This  was  applied  by  means  of  a  hand 
syringe,  and  a  fairly  uniform  mixture  was  obtained  by  dashing 
the  contents  of  the  filled  syringe  back  into  the  vessel  holding 
the  liquids.  Rapid  work  was  the  price  of  a  good  mixture.  This 
practice  is  still  followed  to  a  certain  extent  in  England,  but  is 
rapidly  giving  way  to  more  desirable  methods. 

Soap,  water,  and  kerosene  can  be  so  thoroughly  mixed  to- 
gether that  a  permanent  emulsion  will  be  formed.  Although 
the  product  may  be  a  comparatively  new  one,  the  idea  which 
led  to  its  manufacture  is  not  so  recent.  As  has  already 
been  said,  soap  and  water  formed  the  basis  of  many  mixtures. 
Records  can  be  found  showing  that  nearly  all  insecticides, 
especially  if  they  possess  much  value,  have  at  one  time  or  an- 
other been  used  in  connection  with  soapy  solutions.  It  is  sim- 
ply carrying  out  the  idea  that  if  a  certain  remedy  is  effective, 
its  value  will  be  increased  if  another  substance  also  possessing 
value  be  added  to  it.  Thus  we  find  that  a  correspondent  of 
the  Gardener's  Monthly  says  he  had  used  soap  water  and  crysylic 
acid  together,  first  mixing  them  thoroughly  ;  and  carbolic  acid 
was  applied  in  the  same  manner.1  The  insecticidal  value  of 
kerosene  once  being  known,  it  was  very  natural  that  the  oil  and 
soap  should  be  used  together.  The  first  record  that  I  have 
found  of  such  a  mixture  appeared  in  February,  1875.2  George 
Cruickshank,  of  Whitinsville,  Mass.,  here  says  that  he  had 
been  fighting  the  currant  worm  since  1866,  but  at  first  with 
unsatisfactory  results.  "  In  May,  1870,  I  began  using  kerosene 
with  whale-oil  soap,  increasing  the  kerosene  until  it  would  kill 
the  worm  and  not  injure  the  foliage  of  the  plant.  I  used  5 
pounds  of  whale-oil  soap,  and  1  wine  quart  of  kerosene  to 
25  gallons  of  soft  water  to  mix.  Stir  the  soap  and  kero- 
sene together  till  thoroughly  mixed ;  add  two  pails  of  hot 
water,  stir  till  the  soap  is  dissolved,  then  add  the  balance  of 
cold  water  and  it  is  ready  for  use.  Apply  with  a  syringe  with 
/orce,  in  bright  sunshine.  .  .  .  Where  the  kerosene  and  soap 
was  used,  I  had  no  worms  after  two  years.  In  1873  I  had  a 
barrel  of  the  liquid  all  mixed,  and  ready  for  use  by  the  usual 
time  the  worm  makes  his  appearance,  but  could  find  no  worms 
to  use  it  on."  In  June  of  the  same  year  a  similar  note  ap- 

1  "  T.  A."  in  Gardener's  Monthly,  1868,  Jan.  11. 
>  lUd.  1875,  Feb.  45. 


Kerosene  Emulsions.  81 

peared ; l  Henry  Bird,  of  Newark,  N.  J.,  made  a  mixture  in  which 
he  used  a  little  kerosene  oil  with  strong  soap-suds.  He  said 
that  "  it  readily  combines  and  can  be  applied  uniformly  with 
a  syringe." 

Although  it  is  not  definitely  stated  in  the  two  cases  just 
mentioned  that  emulsions  were  secured,  still  there  can  scarcely 
be  any  doubt  that  at  least  a  part  of  the  oil  was  emulsified. 
Who,  then,  is  the  originator  of  the,  or  a,  kerosene  emulsion  V 
The  answer  is  undoubtedly  to  be  found  in  the  unrecorded  work 
of  some  unknown  but  intelligent  grower  of  plants. 

Cook  was  probably  the  first  experimenter  to  recommend  the 
use  of  a  mixture  of  kerosene  oil  and  soap  water.  He  says :  '2  "I 
found  it  [kerosene]  would  mix  permanently  with  soap  solution 
in  1877  and  1878,  and  that  it  would  kill  many  insects  if  it 
touched  them,  and  best  of  all  would  destroy  haustellate  insects 
like  bugs,  plant  and  scale  lice.  I  first  recommended  this  to  the 
public  in  187&3  .  .  .  The  best  substances  for  such  use  (killing 
haustellate  [sucking]  insects)  are  a  weak  solution  of  carbolic 
acid,  a  strong  suds  either  of  whale-oil  or  common  soap,  and 
tobacco  water.  I  have  found  that  the  addition  of  a  half  tea- 
cupful  of  crude  petroleum  to  two  gallons  of  either  of  the  above 
makes  them  the  more  effective.  ...  I  mix  one  quart  soft 
soap,  or  one-quarter  of  a  pound  of  hard  soap,  with  one  or  two 
quarts  boiling  water ;  as  soon  as  the  soap  is  all  dissolved,  I  stir 
in,  while  all  is  yet  hot,  one  pint  of  kerosene  oil.  This  is  now 
violently  stirred  till  it  is  permanently  mixed  —  that  is,  till 
upon  standing  the  oil  will  not  rise  to  the  top,  but  will  remain 
incorporated  with  the  liquid.  .  .  .  When  we  are  ready  to  use 
this,  stir  in  enough  water  to  make  fifteen  pints  in  all  —  that  is, 
one-fifteenth  of  the  liquid  applied  would  be  kerosene  oil." 
These  formulas,  using  either  the  hard  or  the  soft  soap,  have  re- 
ceived the  name  of  the  originator,  and  they  are  still  in  common 
use. 

Riley  published  the  following  in  the  annual  report  of  the 
Commissioner  of  Agriculture  for  the  years  1881-82,  127 : 
"  Emulsions  with  soap-suds  and  lye  had  been  worked  at  some 

1  "T.  A."  in  Gardener's  Monthly,  1868,  June,  106.    See,  also,  Country  Gen- 
tleman, 1S76,  July  6,  422,  citing  from  The  Agriculturist. 
*  Mich.  Agric.  Exp.  Sta.  1890,  March,  BuU.  58,  5. 
»  See  Rept.  Mich.  State,  Board  of  Agric.  1878,  484. 
6 


82  The  Spraying  of  Plants. 

years  ago  by  Professor  Taylor,  the  microscopist  of  the  Depart- 
ment, and  more  recently  they  have  been  made  by  several  in- 
dependent experimenters  in  Florida,  but  particularly  by  Mr. 
Joseph  Voyle,1  an  intelligent  correspondent  at  Gainsville,  who 
uses  kerosene,  soap,  and  fir-balsam  combined  at  a  high  temper- 
ature and  produces  a  permanent  paste  which  he  calls  «  murvite,' 
readily  soluble  in  water.  Recent  experiments  made  at  our  re- 
quest by  Mr.  Clifford  Richardson,  assistant  chemist  of  the 
Department,  with  ordinary  soap,  whale-oil  soap,  and  both  light 
and  heavy  oils,  also  show  that  20  parts  hard  soap,  10  parts 
water,  40  parts  kerosene,  and  1  part  balsam,  produce  the  most 
satisfactory  results.  .  .  .  Mr.  Hubbard's  experiments  would  in- 
dicate, however,  that  for  insecticide  purposes  nothing  equals 
the  milk  emulsions  which  were  first  suggested  by  Professor 
Barnard  2  during  our  work  on  the  cotton  worm  at  Selma,  Ala., 
in  1880,  and  though  the  use  of  ordinary  emulsifying  agents,  as 
various  mucilaginous  substances  and  the  phosphates,  lactophos- 
phates,  and  hypophosphates  of  lime,  may  facilitate  the  making 
of  kerosene  emulsions,  we  have  not  yet  had  them  sufficiently 
tested  as  insecticides,  and  for  the  present  can  recommend  noth- 
ing more  simple  and  at  the  same  time  more  available  to  the 
average  farmer  than  the  permanent  milk  emulsion  as  produced 
by  Mr.  Hubbard.'* 

During  the  season  1881-82,  Mr.  Hubbard  was  making  exper- 
iments for  the  destruction  of  the  scale  insects  affecting  orange 
trees.  He  made  the  milk  emulsion  only,  and  of  varying 
strengths.  The  following  is  the  formula  recommended  at  the 
close  of  the  season's  work : 8  "  Refined  kerosene,  2  parts  ;  fresh, 
or  preferably  sour,  cow's  milk,  1  part  (percentage  of  oil  66 f). 
Where  cow's  milk  is  not  easily  obtained,  ...  it  may  be  replaced 
by  an  equivalent  of  condensed  milk  (Eagle  brand)  diluted  with 
water  in  the  proportion  1  to  2.  .  .  .  In  applications  for  scale 
insects,  the  kerosene  butter  should  be  diluted  with  water  from 
12-16  times." 

Under  date  of  Sept.  15,  1881,  Mr.  Hubbard  writes  to  Dr. 
Riley  regarding  the  condition  of  the  work  on  orange  scale  then 

1  See  U.  S.  Dept.  of  Agric.  Div.  of  Ent.  Bull.  1, 19. 

2  For  further  details  concerning-  W.  8.  Barnard's  suggestion  of  an  emulsion  of 
milk  and  kerosene,  see  The,  Official  Gazette  U.  S.  Patent  Office,  Vol.  59,  No.  12, 1919. 

8  Ann.  Sept.  U.  S.  Com.  of  Agric.  1881-82,  118,  114. 


Kerosene  Emu  Isions.  83 

in  progress  at  Crescent  City,  Fla.1  "Experiments  with 
Neal's  mixture  gave,  upon  the  whole,  rather  disappointing 
results."  I  have  not  learned  what  was  the  composition  of  this 
mixture,  but  it  may  have  been  an  emulsion  of  kerosene  in  soap 
water,  for  Dr.  Xeal  did  considerable  work  in  this  direction.  On 
Oct.  10,  1882,  he  wrote  from  Archer,  Fla.,  to  the  chief  of  the 
Division  of  Entomology  regarding  these  formulas,  only  two  of 
which  it  is  necessary  to  mention.2  These  were  also  applied  for 
the  destruction  of  the  cotton  worm : 

"1.  Four  pounds  whale-oil  soap  were  dissolved  in  one  gal- 
lon of  water  with  heat ;  to  this,  kerosene  was  added  gradually 
till  it  was  found  that  one  gallon  kerosene  made  a  good  emul- 
sion, capable  of  being  diluted  to  one  per  cent  without  at  once 
disintegrating. 

"2.  Four  pounds  resin  soap,  common  bar  or  yellow  soap, 
were  dissolved  in  one  gallon  water.  One  gallon  kerosene  grad- 
ually added,  with  constant  agitation.  The  greater  the  per  cent 
of  resin  in  the  soap,  the  better  was  the  emulsion  I  found  it 
made,  which  would  indicate  that  such  a  soap  for  this  purpose 
would  no  doubt  be  a  valuable  article  in  the  market." 

On  Nov.  28,  1882,  Hubbard  wrote  in  detail  concerning 
the  use  of  kerosene,  and  also  criticised  Neal's  formulas.  He 
says : 3 

"  Experiments  made  in  September  with  kerosene  washes  on 
purple  scale  show  that  the  eggs  are  much  more  difficult  to  kill 
than  I  had  supposed.  They  have  been  killed  by  66  per  cent 
kerosene  and  soap  emulsions  diluted  1  to  9.  ...  I  have  care- 
fully gone  over  Dr.  Neal's  report  and  have  a  few  comments  to 
add  to  my  former  communication. 

"  Dr.  Neal  says  *  the  greater  the  percentage  of  resin  in  the 
soap  the  better  the  emulsion  I  found  it  made.'  This  may  be 
true  of  the  emulsion,  but  when  diluted,  the  resin,  or  a  large  part 
of  it,  separates  from  the  liquid  and  forms  a  waxy  scum  on  the 
surface,  which  clogs  the  pump  and  nozzle,  and  is  troublesome 
unless  removed.  .  .  .  The  strongest  emulsion  used  by  Dr.  Neal 
contains  50  per  cent  of  oil  and  the  strongest  wash  a  dilution  of 
1  to  9.  My  experiments  with  milk  emulsion  of  this  strength 
did  not  in  the  end  prove  satisfactory,  and  I  long  ago  decided  to 

*  V.  S.  Dept.  ofAgric.  Div.  of  Ent.  1883,  Bull.  1,  10. 
2  Ibid.  32.  a  Ibid.  17,  18. 


84  The  Spraying  of  Plants. 

increase  the  amount  of  oil  in  the  emulsion.  I  now  use  66  per  cent 
emulsion  diluted  1  to  9,  and  these,  although  sufficiently  strong 
for  long  scale,  are  not  sufficiently  penetrating  to  kill  the  eggs  of 
purple  scale.  .  .  .  The  following  are  my  estimates  for  a  stan- 
dard wash  of  whale-oil  soap  and  kerosene,  emulsion  66  per  cent 
oil,  diluted  to  1  to  9  (one  gallon  emulsion  =  10  gallons  wash)  : 
whale-oil  soap,  £  pound ;  water,  1  gallon ;  kerosene,  2  gallons." 

In  the  annual  report  of  the  Commissioner  of  Agriculture  for 
1884  a  formula  is  published  which  contains  twice  as  much 
soap  as  Hubhard's  original  one,  the  other  ingredients  remaining 
the  same.  This  has  become  most  commonly  known  under  the 
name  of  the  Riley-Hubbard  formula  for  the  kerosene  emulsion, 
and  is  used  to-day  unchanged.  It  is  prepared  as  follows  : 

"  Kerosene,  2  gallons  ;  common  soap,  £  pound ;  water,  1  gallon. 

"  Heat  the  mixture  of  soap  and  water  and  add  it  boiling  hot 
to  the  kerosene.  Churn  the  mixture  by  means  of  a  force  pump 
and  spray  nozzle  for  five  to  ten  minutes.  The  emulsion,  if  perfect, 
forms  a  cream,  which  thickens  on  cooling,  and  adheres  without 
oiliness  to  the  surface  of  the  glass.  Dilute  with  cold  water 
before  using,  to  the  extent  which  experience  will  indicate  is 
best." 

The  scale  insects  found  upon  the  orange  trees  in  California 
may  be  cited  as  further  examples  showing  that  obstacles  can  be 
overcome  if  only  sufficient  attention  is  directed  towards  them. 
These  insects  were  a  serious  pest  on  the  Pacific  coast,  and  they 
are  not  entirely  under  control  even  at  the  present  day,  but  their 
great  numbers  in  former  years  aroused  the  fruit  growers  to  ener- 
getic measures.  Many  compounds  were  recommended  for  the 
treatment  of  the  pests.  The  preparations  were  generally  in  liquid 
form,  and  may  be  considered  as  rather  elaborate  outgrowths  of 
compounds  whose  value  had  long  been  known.  The  following 
are  good  examples  of  these  remedies,  whose  number  was  almost 
endless : l 

1.  Forty-six  pounds  whale-oil  soap,  4  gallons  coal  oil,  100 
gallons  water. 

2.  Twenty-five  pounds  brown  soap,  6  pounds  wood  potash,  4 
gallons  coal  oil,  100  gallons  water. 

iEllwood  Cooper,  "California  Fruit  Culture,"  a  report  of  the  fifth  annual  con- 
vention of  California  fruit  growers. 


Resin  Soaps.  85 

3.  Ten  pounds  whale-oil  or  other  soft  soap,  2£  or  3  pounds 
sulphur,  1  gallon  coal  oil,  17  gallons  water. 

It  will  be  seen  that  soap  or  kerosene,  or  both,  formed  the 
basis  of  most  of  these  washes.  They  were  not  entirely  satis- 
factory, for  some  reason  still  unexplained.  In  1886,  D.  W. 
Coquillett  and  Albert  Koebele,  were  appointed  by  the  Depart- 
ment of  Agriculture  to  investigate  the  trouble,  for  in  the  East 
such  emulsions  were  used  almost  invariably  with  good  results. 

In  a  review  of  their  work,  published  in  1887,  Dr.  Riley  makes 
the  following  statements,  which  indicate  well  the  character  of 
these  investigations : 1 

"  Among  the  different  substances  thoroughly  experimented 
with  were  caustic  potash,  caustic  soda,  hard  and  soft  soaps, 
tobacco  soap,  whale-oil  soap,  vinegar,  Paris  green,  resin  soaps, 
and  compounds,  and  so  on.  .  .  .  Mr.  Koebele's  attention  was, 
however,  directed  mainly  to  the  preparation  of  resinous  soaps 
and  compounds  on  account  of  their  greater  cheapness.  He  suc- 
ceeded in  making  a  number  of  these  mixtures,  which,  when 
properly  diluted,  need  not  cost  more  than  one-half  to  one  cent 
per  gallon,  and  which  produce  very  satisfactory  results,  killing 
the  insects  or  either  penetrating  or  hardening  the  egg  masses 
so  as  to  prevent  the  hatching  of  the  young.  One  of  the  most 
satisfactory  methods  of  making  a  resin  soap  is  to  dissolve  1 
pound  of  caustic  soda  in  1^  gallons  water  to  produce  the  lye ; 
then  dissolve  2  pounds  resin  and  1  pound  tallow  by  moderate 
heat,  stirring  in  gradually  during  the  cooking  1  quart  of  the 
lye,  and  then  adding  water  until  you  have  about  22  pints  of 
a  brown  and  thick  soap-  This  will  make  44  gallons  of  wash, 
costing  less  then  one-half  cent  per  gallon." 

A  few  further  suggestions  were  made  regarding  various 
combinations  of  the  above  mixture,  and  the  addition  of  adhesive 
substances  to  the  washes  was  strongly  advised.  But  the  most 
important  part  of  this  address  was  the  emphasis  laid  upon  the 
value  of  the  resin  washes,  for  from  this  time  on  they  were  destined 
to  extensive  use  in  the  orange  district  of  California. 

1  Address  by  Professor  C.  V.  Kiley  before  the  California  State  Board  of  Horticul- 
ture, at  its  seini-annual  session  at  EiA-erside,  Cal.,  April  12,  1SS7,  as  reported  in  the 
Pacific  Rural  Press,  April  23,  1887,  cited  in  Bull.  15  U.  S.  Dept.  of  Agrie.  Div. 
of  Ent.  16,  17.  See  also  Ann.  Hept.  U.  S.  Com.  of  Ayric.  1SS6,  558,  giving  details 
of  Koebele' s  work. 


86  The  Spraying  of  Plants. 

During  1887  Koebele  tested  the  value  of  the  addition  of 
arsenic  acid  to  kerosene  emulsion.  In  his  report  to  the  Ento- 
mologist, dated  December,  1887,  he  says  : 1  "  In  the  main  I  have 
followed  your  suggestion  while  here  in  April  last,  in  preparing 
the  kerosene  emulsion,  viz.  to  emulsify  with  resin  compound, 
and  use  the  arsenic  acid  in  addition.  I  am  glad  that  your 
hopes  in  this  wash  are  verified.  In  every  instance  where  your 
proposed  arsenic  acid  was  added,  either  to  emulsified  kerosene 
or  resin  compound,  there  has  been  a  complete  extermination 
of  the  scales."  Although  such  washes  were  here  favorably 
reported  upon,  they  have  not  come  into  general  use. 

The  next  year  another  valuable  contribution  was  made  upon 
this  subject,  of  which  the  following  abstracts  are  the  most 
important : 2 

"Caustic  solutions  have  the  disadvantage  of  hurting  the 
tree,  and  are  not  especially  adapted  to  penetrate  into  the  egg- 
sac,  which,  on  account  of  its  peculiar  texture,  repels  most 
liquids. 

"Various  soap  solutions,  some  containing  kerosene  and  some 
whale-oil,  have  proved  fair  remedies,  but  cannot  in  my  opinion 
be  equaled  by  the  resin  solutions,  of  which  we  give  three 
formulas.  The  first  was  tried  by  Mr.  A.  Koebele,  the  second 
by  Mr.  Alexander  Craw,  of  Los  Angeles ;  the  third  has  been 
given  me  by  Mr.  L.  D.  Green  of  Sacramento.  From  personal 
experiments  with  them  all  I  am  well  satisfied  with  thenio 

"  Recipe  No.  1.  Four  pounds  resin,  3  pounds  sal-soda,  water 
to  make  36  pints.  Dissolve  the  sal-soda  in  a  few  pints  of  water ; 
when  thoroughly  dissolved,  add  the  resin.  Heat  until  dissolved, 
and  add  water  finally.  Use  two  quarts  of  solution  to  the  gallon 
of  water.  Use  at  a  temperature  of  about  100°  F. 

"  Recipe  No.  2.  One  pound  caustic  soda,  10  pounds  resin, 
100  gallons  water.  Prepare  as  above. 

"  As,  perhaps,  owing  to  the  nature  of  the  caustic,  the  leaves 
are  sometimes  liable  to  be  affected,  I  should  recommend  the 
spraying  of  the  tree  with  pure  water  liberally  (the  water  will 
free  the  pores  of  the  leaves)  two  or  three  days  after  the  appli- 
cations of  the  resin  solutions. 

1  Ann.  Kept.  U.  S.  Com.  of  Agric.  188T,  143-1 4T. 

2  Klee,  "  A  Treatise  on  the  Insect  Injuries  to  Fruit  and  Fruit  Trees  of  the 
State  of  California,"  1888,  Oct.  12,  28,  29. 


History  of  Fungicides  in  America.  87 

"  These  solutions  being  cheap,  they  may  be  used  liberally, 
and  two  or  three  treatments  a  year  would,  I  think,  keep  the 
trees  in  fair  order. 

"Recipe  No.  3.  Sixty  pounds  resin,  60  pounds  tallow,  10 
pounds  potash,  dissolved  in  10  gallons  water  ;  10  pounds  caustic 
soda  (Green  bank,  98  per  cent).  Dissolve  the  resin  and  tallow  ; 
when  dissolved,  add  caustic  water  slowly.  After  mixture  is 
made,  add  10  gallons  of  water.  Use  at  the  rate  of  1  gallon  of 
mixture  to  10  gallons  of  water. 

"  In  the  case  of  the  black  scale,  I  have  found  the  addition  of 
sulphide  of  soda  at  the  rate  of  1  gallon  to  75  of  resin  solution 
(the  strength  of  the  sulphide  being  1  pound  of  concentrated 
lye  to  2  pounds  of  sulphide)  beneficial,  and  I  should  recommend 
the  trial  of  this  for  icerya." 

D.  W.  Coquillett,  assistant  in  the  Division  of  Entomology, 
continued  the  work  begun  by  Koebele  in  regard  to  the  de- 
struction of  scale  insects,  and  at  the  end  of  the  year  1889  the 
following  was  recommended  as  "  the  best  solution  for  use  dur- 
ing the  latter  part  of  the  year  " :  it  was  made  by  combining 
with  heat,  "  resin,  18  pounds ;  caustic  soda  (70  per  cent  strong), 
5  pounds;  fish-oil,  2|  pints;  water  to  make  100  gallons."1  A 
slightly  modified  formula  was  published  the  following  year ;  the 
fish-oil  was  omitted,  and  5  pounds  of  caustic  soda  (77  per  cent) 
were  used  with  40  pounds  of  resin,  this  being  sufficient  to  make 
50  gallons  of  the  wash.2  Formulas  almost  identical  to  these 
are  in  use  at  the  present  time  and  are  highly  valued  for  the 
destruction  of  orange-scale  insects,  but  fish-oil  is  very  commonly 
added  to  the  preparations. 

History  of  the  Fungicides. 

This  country  has  been  less  energetic  in  the  introduction  of 
new  fungicides,  probably  because  fungi  have  always  been  more 
or  less  serious  here,  and  growers  were  accustomed  to  their 
presence.  A  special  stimulus  appears  to  be  necessary  to  arouse 
a  people  to  any  new  line  of  thought,  and  if  this  is  not  present, 
progress  is  slow.  The  American  mildews,  introduced  into 
France,  forced  the  vineyardists  in  the  affected  districts  to 

i  Ann.  Sept.  U.  S.  Com.  of  Agrio.  1889,  355.  »  Ibid.  1890,  263. 


88  The  Spraying  of  Plants. 

discover  some  efficient  remedy,  and  they  did  so.  The  appear- 
ance in  the  Central  States  of  the  potato  beetle  and  the  canker- 
worm  exerted  a  similar  influence  on  American  farmers ;  they 
also  were  forced  to  overcome  the  pests,  and  the  result  was  as 
successful  as  could  have  been  wished.  When  each  country  had 
entered  upon  the  task  allotted  to  it,  the  next  step  would  natu- 
rally be  a  mutual  exchange  of  results  that  might  be  beneficial  to 
the  other,  and  such  exchanges  have  taken  place.  Americans 
have  riot  been  slow  to  test  many  of  the  excellent  practices  recom- 
mended by  French  investigators,  but  when  the  methods  were 
once  understood  they  have  been  adopted  in  all  parts  of  the 
land,  at  least  by  a  few  growers,  with  astonishing  rapidity ;  and 
so  well  has  the  information  regarding  these  remedies  been  dis- 
seminated that  no  man  now  has  an  excuse  for  not  knowing 
how  to  treat  the  large  majority  of  the  troubles  which  affect  the 
plants  that  he  grows. 

Little  was  known  in  this  country  regarding  the  treatment  of 
fungous  diseases  of  plants  by  liquid  applications  previous  to 
1885.  Saunders  and  Goff  were  the  pioneers  in  the  work.  The 
former,1  in  1884,  suggested  the  use  of  three  fungicides  for  the 
treatment  of  apple  scab :  Hyposulphite  of  soda,  applied  for 
the  first  time,  in  proportion  of  1  pound  to  10  gallons  of  water : 
sulphide  of  lime,  made  by  boiling  2  pounds  of  sulphur  and  1 
pound  of  quicklime  in  2  gallons  of  water,  stirring  frequently 
till  of  a  reddish  yellow  color ;  after  settling,  the  clear  liquid  is 
poured  off :  a  mixture  of  sulphur  and  water,  in  the  proportion 
of  1  pound  to  10  or  15  gallons  of  water.  The  same  remedies 
were  also  recommended  by  Goff  for  the  apple  scab  and  leaf- 
blight.  During  the  following  year  he  tested  the  hyposulphite 
of  soda  with  the  result  that  "  in  the  syringed  portion  of  the 
tree,  the  per  cent  of  uninjured  fruits  was  double  that  in  the  un- 
syringed  portion,  while  the  percentage  of  the  third  quality,  or 
much  injured  fruits,  was  one-half  less.  It  also  appears  that  all 
of  the  fruits  on  the  syringed  portion  were  larger  in  size  than 
those  on  the  un syringed  portion.  We  also  noted  that  there 
were  many  more  decayed  fruits  on  the  unsyringed  portion  of 
the  tree."  2  These  were  the  first  of  innumerable  experiments 
regarding  the  treatment  of  the  same  diseases. 

*  Canadian  Horticulturist,  1884,  vii.  No.  6,  127. 

*  Awn,.  Rep.  N.  Y.  State  Agric.  Exp.  Sta.  1885,  260. 


Former  Treatments  of  G-rape  Diseases.         89 

Colonel  Alexander  W.  Pearson,  of  Vineland,  N.J.,  summed 
up  the  situation,  regarding  vineyard  diseases,  in  a  comprehen- 
sive article  which  was  published  in  1886.1  He  says :  "  Years 
ago,  while  experimenting  with  sundry  chemicals  designed  in 
their  application  to  prevent  or  cure  'the  rot,'  I  accidentally 
noticed  a  vine,  one  branch  of  which  was  trained  beneath  the 
shelter  of  a  projecting  cornice,  while  the  other  ran  over  a 
trellis  exposed  to  the  sky.  The  grapes  beneath  the  cornice 
were  sound;  those  exposed  were  rotten."  Acting  upon  this 
hint,  Colonel  Pearson  made  a  board  covering,  twenty  inches 
wide,  over  a  portion  of  his  trellis,  and  the  following  year  he 
found  that  the  fruit  under  the  shelter  was  sound,  while  that 
which  projected  beyond  was  injured  as  well  as  all  others  which 
were  unprotected.2  The  year  following,  the  boards  were  re- 
placed by  cotton  sheeting  a  yard  wide,  which  was  regularly 
used  afterwards.  Paper  bags  were  also  tried,  these  being  tied 
about  the  fruit.  They  also  afforded  excellent  protection,  but 
their  use  was  rather  expensive,  so  that  the  main  reliance  was 
placed  upon  the  cloth  coverings,  which  in  addition  protected 
the  foliage  from  the  downy  mildew. 

In  1882,  Colonel  Pearson  selected  a  block  of  Concords  from 
which  he  u  had  the  symptoms  of  infection  removed  as  fast  as 
they  appeared.  All  the  rotted  grapes  were  picked  weekly  from 
the  clusters,  picked  up  from  beneath  the  trellis,  taken  away,  and 
buried.  The  leaves,  wherever  spotted  with  the  phoma  [black 
rot],  were  also  gathered."  The  following  year  "the  vines  thus 
cleaned  showed  an  improvement  of  at  least  50  per  cent  in  their 
crop.  Plowing  all  debris  under,  late  in  the  spring,  and  then 
leaving  the  ground  undisturbed,  also  proved  beneficial."  These 
processes  of  disinfection  were  considered  as  forming  the  surest 
and  most  practicable  means  for  the  prevention  of  rot  on  grapes. 

Vines  that  were  well  nourished  were  supposed  to  resist  disease 
better  than  their  weaker  neighbors,  the  downy  mildew  in  par- 
ticular being  influenced  by  this  variation.  In  other  respects 
this  fungus  was  treated  with  difficulty :  "  There  is  no  benefit 
from  any  method  of  disinfection,  which  I  have  tried.  Sulphur 

1  Scribner,  U.  S.  Dept.  of  Agric.  Bot.  I>ic.  Bull.  ii.  "Keport  on  the  Fungous 
Diseases  of  the  Grape  Vine,"  Appendix  B.  "  Kemarks  on  Grape  Eot  and  Grape  Mil- 
dew," 54-63. 

*  This  remedy  was  not  new.    See  Ann.  Kept.  U.  S.  Com.  of  Agric.  1861,  498. 


90  The  Spraying  of  Plants. 

is  inefficient,  and  the  burial  of  the  vineyard  debris  and  subse- 
quent non-culture,  which  are  of  avail  against  the  phonia,  are 
useless  here.  When  atmospheric  conditions  favor  the  develop- 
ment of  this  pest,  it  spreads  like  a  prairie  fire.  I  have  seen  the 
foliage  on  ten  thousand  vines  completely  blasted  by  mildew 
within  three  days  after  its  appearance.  Our  only  defense 
against  peronospora  will  be  in  constitutional,  prophylactic 
treatment." 

The  above  review  was  made  by  one  of  the  most  intelligent 
vineyardists  in  the  country.  It  shows  how  comparatively  help- 
less grape  growers  were  in  controlling  fungous  diseases,  although 
Colonel  Pearson  himself  had  obtained  good  results.  In  the  trial 
of  chemicals  of  which  he  speaks,  many  articles  must  have  been 
tested,  but  apparently  none  proved  of  value.  In  1880,  however, 
another  experimenter  appears  to  have  been  more  fortunate :  * 
"A  writer  in  the  California  Horticulturist  speaks  of  the  success 
of  the  application  of  sulphate  of  copper  for  mildew  on  rose 
bushes,  using  one-half  ounce  to  a  pail  of  wrater."  But  this  note 
did  not  attract  any  particular  attention,  in  which  respect  it 
resembles  a  similar  one  which  appeared  in  an  English  journal 
in  1861  (see  page  17). 

During  1884  a  substitute  for  Paris  green  was  mentioned  in 
the  Country  Gentleman.2  Although  its  use  as  an  insecticide 
was  advised  in  later  years,  a  similar  preparation  was  also 
thoroughly  tested  in  regard  to  its  fungicidal  value.  It  was 
made  by  dissolving 

Copperas 1  pound. 

Water. 4  gallons. 

When  dissolved  add  to  this  solution 

Slaked  lime I  pound. 

The  Americans  were  thus  hovering  about  the  truth,  but  they 
did  not  quite  discern  it.  The  discovery  was  made  by  the  French, 
and  much  of  the  preliminary  work  necessary  to  the  develop- 
ment of  this  new  idea  was  also  done  by  them. 

The  first  formula  for  the  manufacture  of  a  fungicide  that 
was  borrowed  from  the  French  was  for  making  the  material 
which  was  later  known  as  the  Bordeaux  mixture.  It  was  pub- 

»  Coun.try  Gentleman,  1880,  April  22,  262.  2  Ibid.  1884,  July  IT,  59T. 


Former  Treatments  of  drape  Diseases.         91 

lished  by  F.  Lamson-Scribner,  at  that  time  assistant  botanist 
in  the  Department  of  Agriculture  at  Washington,  in  the  annual 
report  of  the  Commissioner  of  Agriculture  for  the  year  1885, 
although  it  actually  appeared  earlier  in  articles  published  by 
the  Section  of  Vegetable  Pathology  which  bear  a  later  date. 
On  page  84  of  this  report  may  be  found  the  following  para- 
graph • 

"  Many  remedies  for  the  disease  of  the  vine  due  to  the 
peronospora  have  been  proposed,  but  so  far  the  most  effectual 
specific  known  is  a  solution  of  lime  and  sulphate  of  copper.  It 
is  made  by  dissolving  18  pounds  of  sulphate  of  copper  in  about 
22  gallons  of  water ; 1  in  another  vessel  mix  34  pounds  of  coarse 
lime  with  6  or  7  gallons  of  water,  and  to  this  solution  add  the 
solution  of  copper.  A  bluish  paste  will  be  the  result,,  This 
compound,  when  thoroughly  mixed,  is  brushed  over  the  leaves 
of  the  vine  with  a  small  broom,  care  being  taken  not  to  touch 
the  grapes.  This  remedy,  it  is  asserted,  will  not  only  destroy 
the  mildew,  but  will  prevent  its  attacks."  This  preparation 
was  at  first  known  as  "  the  copper  mixture  of  Gironde." 

The  following  statements,  no  less  interesting  than  the  above, 
may  be  found  on  page  81  of  the  same  report :  "  Many  of  the 
diseases  of  our  fruit  orchards  might  be  remedied,  or  at  least 
diminished,  by  raking  together  and  burning  the  leaves  as  soon 
as  they  have  fallen.  .  .  .  The  plan  of  raking  up  the  leaves  and 
burning  them  has  been  especially  recommended  as  a  means  of 
checking  the  growth  of  the  apple-scab  fungus,  and  the  pear- 
tree  scab.  In  respect  to  the  latter  disease,  it  is  not  confined  to 
the  leaves  and  fruit,  but  extends  to  the  young  shoots  also.  .  .  . 
If  this  disease  be  taken  early,  say  at  the  time  of  the  formation 
of  the  conidial  or  summer  spores  (the  only  spores  so  far  known), 
the  direct  application  of  some  fungicide  might  prove  beneficial. 
Experiments  alone  will  prove  the  usefulness  of  this." 

Here,  then,  are  the  first  indications  of  a  future  which  could 
scarcely  have  been  prophesied  at  the  time,  even  by  the  boldest 
imagination ;  wre  have  a  hint  of  a  power  whose  influence  was 
destined  to  bring  the  growing  of  plants  largely  out  of  the  realm 
of  chance,  so  far  as  fungous  diseases  are  concerned,  and  with 

1  This  amount  of  water  is  undoubtedly  given  as  an  equivalent  of  the  French 
hectoliter.  But  the  French  measure  is  equivalent  to  26.41T  gallons  of  the  standard 
United  States  measures.  See  Appendix. 


92  The  Spraying  of  Plants. 

the  help  of  the  knowledge  already  acquired,  to  place  this  art 
upon  a  footing  even  more  firm  than  that  enjoyed  by  those  occu- 
pations in  which  the  weather  and  other  dispensations  of  Provi- 
dence have  no  direct  influence.  The  passage  contains  the  germ 
of  an  educational  movement  which  stands  unparalleled  in  the 
effect  it  has  had  in  broadening  the  horizon  of  the  agriculturist 
of  the  United  States.  It  has  forced  him  to  see  that  there  is 
more  in  his  business  than  following  the  rule-of-thumb  processes 
so  long  in  vogue.  It  has  emphasized  the  power  of  knowledge, 
and  it  has  demonstrated,  and  is  daily  impressing  the  fact  upon 
all  who  take  the  trouble  to  see,  that  it  requires  more  brains 
than  brawn  to  succeed  in  an  occupation  at  which  formerly 
even  the  most  ignorant  could  be  at  least  fairly  successful.  The 
ignorant  are  going  to  the  wall,  and  it  is  the  educated  man,  the 
"  book  farmer,"  who  is  pushing  them  along,  and  who  fills  their 
places  when  they  are  gone.  The  fittest  stand  the  best  chance 
of  surviving. 


TJie   Warfare  against  the  various  Fungous  Diseases. 

The  formula  for  the  manufacture  of  the  Bordeaux  mixture 
was  soon  widely  copied.  The  following  year,  1886,  it  was 
published  by  Hilgard  in  January,1  by  Riley  in  February,2  by 
Colman  in  May,8  and  again  by  Scribner  in  the  government 
reports.4 

In  Hilgard's  report  the  remark  is  made  that  attention  was 
called  to  the  mixture  at  an  earlier  date  in  the  Pacific  Rural 
Press.  No  other  fungicide  is  mentioned,  but  some  remarks 
are  made  concerning  the  value  and  use  of  the  mixture  in 
France.  Dr.  Riley's  article  is  on  "  The  Mildew  of  the  Grape 
Vine  " ;  it  mentions  the  Bordeaux  mixture,  and  also  the  use  of 
kerosene-milk  emulsion,  sulphur  and  lime,  and  carbolic  acid. 

It  was  during  1886  that  the  Section  of  Vegetable  Pathology 
was  established  as  a  part  of  the  United  States  Department  of 
Agriculture.  F.  Lamson-Scribner  was  appointed  its  chief,  and 
in  May  there  appeared  the  first  publication,  Circular  No.  1, 

i  Calif.  Agric.  Exp.  Sto.  1886,  Jan.  Bull.  51. 

»  Rural  Neic- Yorker,  1886,  Feb.  6,  87 

»  U.  S.  Dept.  of  Agric.  Sot.  Div.  Sec.  Veg.  Path.  1886,  May,  CIr.  1 

*  Ibid.  Bull.  ii.  16 ;  Ann.  Rept.  U.  S.  Com.  of  Agric.  1886,  100. 


Treatments  for  Downy  Mildew.  93 

entitled:  "Treatment  of  the  Downy  Grape  Mildew  (Perono- 
spora  viticold)  and  the  Black  Rot  (Phoma  uvicold)"  The  five 
remedies  mentioned  in  this  circular  were  all  copied  from  the 
French  journals.  The  directions  were  in  brief  as  follows : 

"  For  Peronospora. 

1.  "Dissolve  in  10  gallons  of  water  5  pounds  of  the  sulphate 
of  copper."     This  was  to  be  used  for  soaking  the  stakes  and  all 
tying  material,  and  was  also  to  be  sprayed  upon  the  foliage, 
using  for  the  purpose  any  fine  spraying  apparatus,  the  cyclone 
nozzle  being  suggested  as  the  best  for  the  purpose. 

2.  "  Make  a  mixture  of  lime  and  water,  as  one  ordinarily 
applies  whitewash."     Apply  as  above,  but  repeat  after  rains. 

3.  This  was  the  formula  for  the  "  copper  mixture  of  Gironde," 
as  given  on  a  preceding  page. 

4.  "  The  powder  of  Podechard."     This  contained  225  pounds 
of  air-slaked  lime,  45  pounds  of  sulphate  of  copper,  20  pounds  of 
flowers  of  sulphur,  30  pounds  unleashed  ashes,  and  15  gallons  of 
water. 

5.  "  The  ordinary  milk-kerosene  emulsion,  with  the  addition 
of  from  2  to  5  per  cent  of  carbolic  acid  and  the  same  percentage 
of  glycerine,  and  then  dilute  1  part  of  the  emulsion  in  20  to  50 
parts  of  water.     Spray  on  the  under  surface  of  the  leaves  by 
means  of  a  cyclone  nozzle  of  small  aperture."  J 

For  black  rot,  the  mixture  of  lime  and  sulphate  of  copper 
was  particularly  recommended,  and  in  addition  to  this  a  free 
use  of  Podechard's  powder,  upon  the  ground  in  the  vineyard, 
was  advisable. 

Scribner  wrote  as  follows  concerning  the  above  circular : 
"  Three  thousand  of  these  circulars  were  distributed,  and  I 
have  reason  to  believe  that  many  made  a  trial  of  one  or  more 
of  the  remedies  proposed,  but  I  regret  to  say  that  few  responded 
to  the  request  that  the  results  of  these  trials  be  reported  to  the 
Department."2  A  report  was  received  from  George  M.  High, 
Middle  Bass,  Ohio,  the  letter  being  dated  Dec.  28,  1886,  in 
which  he  speaks  of  having  poor  success  with  formula  Xo.  2, 

1  This  formula  had  previously  been  published  by  Riley  in  Rural  New-  Yorker, 
1886,  Feb.  6. 

'Ann.  Sept.  U.  S.  Com.  of  Agric.  1886, 100. 


94  The  -Spraying  of  Plants. 

but  No.  3  was  very  promising.  He  also  used  the  following  upon 
sixty  Catawba  vines :  "  Dissolve  1  pound  of  sulphate  of  copper 
in  2  gallons  of  water ;  in  another  vessel  slake  4  pounds  of  lime  in 
the  same  quantity  of  water;  then  mix  these  together  thoroughly. 
The  advantage  was  the  preservation  of  the  foliage  in  a  healthy 
condition  in  a  marked  degree  over  vines  untreated."  l 

Bush  &  Son  &  Meissner,  of  Bushberg,  Mo.,  also  reported 
their  work,  saying :  "  We  have  tried  all  the  remedies  recom- 
mended in  your  circular  and  find  that  designated  as  No.  3  the 
best.  We  are  continuing  to  apply  this  mixture  of  lime  with 
dissolved  sulphate  of  copper  (not  too  strong),  with  confidence 
in  its  good  results."2  Another  correspondent  stated  that  he 
used  Podechard's  powder  (No.  4)  with  marked  benefit. 

The  second  publication  of  the  Section  of  Vegetable  Pathology 
was  a  "Report  on  the  Fungous  Diseases  of  the  Grape  Vine."8 
It  is  a  bulletin  of  one  hundred  and  thirty-six  pages,  and  gives 
exhaustive  descriptions  of  the  fungi  causing  the  downy  mildew 
(Peronospora  viticola),  the  powdery  mildew  (Uncinula  spiralis), 
the  black  rot  (Physalospora  Bidwellii),  anthracnose  (Sphaceloma 
Ampelinum),  grape  leaf  blight  (Cercospora  viticola),  and  grape 
leaf  spot  (Phyllosticta  Labruscce).  The  botanical  structure,  the 
general  appearance,  conditions  of  development,  and  similar 
points  were  dwelled  upon,  so  that  this  may  be  considered  as 
perhaps  the  most  important  publication  of  the  section,  when 
one  considers  the  influence  that  it  exerted  not  only  upon  grape 
growers,  but  upon  horticulturists  in  general. 

The  remedies  recommended  against  the  downy  mildew  were 
mostly  those  in  use  by  French  and  Italian  vineyardists,  viz. 
the  mixture  of  copper  sulphate  and  lime,  and  the  milk  of 
lime  alone.  There  is  also  published  a  letter  from  Dr.  John 
Strentzel,  of  Martinez,  Cal.,  dated  June  28,  1886,  in  which 
the  following  statements  are  made  concerning  the  use  of  iron 
and  copper  sulphates  : 4  "I  have  been  using  for  years  solutions 

1  Ann.  Kept.  U.  S.  Com.  of  Agric.  1886,  101.    See  also  Country  Gentleman, 
1887,  April  28,  340. 

2  Ibid.  loc.  cit. 

8  This  was  Bull.  ii.  of  the  Section,  Bull.  i.  having  been  published  on  a  botanical 
subject  not  related  to  the  work  of  the  Section. 

4  Scribner,  "  Report  on  the  Fungous  Diseases  of  the  Grape  Vine,"  U.  S.  Dept. 
of  Agric.  Sec.  Veg.  Path.  Bull.  ii.  IT. 


Treatments  for  Grape  Diseases.  95 

of  sulphates  of  copper  and  iron  to  destroy  parasitic  fungi  on 
vines  and  pear  trees,  also  to  kill  red  spider  on  almonds.  .  .  . 
The  mixture  I  use  consists  of  2  pounds  of  sulphate  of  iron  to  1 
gallon  of  water,  dissolved,  and  add  3  pounds  of  lime  and 
1  pound  of  sulphur,  the  lime  being  slaked  in  hot  salt  brine 
to  a  consistency  of  thick  whitewash."  The  removal  of  diseased 
fruit,  leaves,  and  canes  is  also  recommended,  in  addition  to  the 
liquid  applications. 

The  powdery  mildew  was  best  treated  by  the  use  of  a  mixture 
recommended  by  J.  F.  Allen.1  It  is  composed  of  sulphur  and 
lime,  and  is  almost  identical  with  Grison's  liquid  described  on 
page  16. 

Against  black  rot,  it  was  advised  to  wash  "  the  vines  in  early 
spring,  before  the  buds  have  commenced  to  swell,  with  a  strong 
solution  of  the  sulphate  of  iron,"  but  the  main  reliance  was  to 
be  placed  in  the  bagging  of  the  fruit. 

Anthracnose  was  to  be  controlled  by  the  European  practice  of 
"  washing  the  vines  in  early  spring,  before  the  buds  have  com- 
menced to  expand,  with  a  strong  solution  (50  per  cent)  of 
sulphate  of  iron.  .  .  .  When  the  young  shoots  have  attained 
a  length  of  five  or  six  inches,  they  receive  a  good  dusting  with 
the  flowers  of  sulphur,  whether  the  disease  has  appeared  on 
them  or  not." 

As  regards  the  other  two  diseases  mentioned  in  the  bulletin, 
no  remedies  were  then  known,  but  it  was  thought  "probable 
that  the  general  treatment  advocated  for  the  downy  mildew 
and  anthracnose  will  have  a  direct  tendency  to  limit  their 
development." 

Three  appendices  form  about  two-thirds  of  this  bulletin. 
Appendix  A,  written  by  Erwiu  F.  Smith,  gives  an  account  of 
the  extent  and  severity  of  fungous  disease  on  grapes,  and  some 
of  the  more  common  methods  of  treatment.  The  material  was 
compiled  from  the  answers  received  to  a  circular  asking  for 
information  on  these  topics. 

Appendix  B  was  written  by  Colonel  A.  W.  Pearson.  It  is 
an  article  on  "Remarks  on  Grape  Rot  and  Grape  Mildew," 
which  has  already  been  quoted  in  these  pages. 

Appendix  C  is  entitled  "The  Prevention  of  Mildew  —  Re- 
sults of  Experiments  with  Various  Fungicides  in  French  and 

*  U.  S.  Patent  Office  Rept.  Agric.  1854,  312. 


96  The  Spraying  of  Plants. 

Italian  Vineyards  in  1885."  Sixty-eight  pages,  or  one-half  of 
the  bulletin,  are  devoted  to  this  subject,  and  it  forms  a  fitting 
close  to  the  matter  which  precedes.  Its  contents,  coming,  as  it 
were,  directly  from  the  European  vineyards,  which  were  suffer- 
ing even  more  severely  than  ours,  lent  a  weight  to  the  whole 
publication  which  greatly  increased  its  value.  The  subjects 
treated  in  the  various  abstracts  have  already  been  discussed  in 
the  preceding  chapter  of  this  volume. 

The  annual  report  of  the  mycological  Section l  for  1886  con- 
tains much  interesting  matter.  The  Section  seems  to  have  been 
placed  in  good  working  order  from  the  time  of  its  establish- 
ment, and  many  important  descriptions  and  recommendations 
are  contained  in  this  report,  a  very  complete  review  of  the  work 
carried  on  in  France  and  Italy  being  given.  An  abstract  of 
Millardet's  article  on  the  work  done  during  the  year  mentions 
many  of  the  substances  tried  in  France,  the  best  of  which  are 
"  the  copper  mixture  of  Gironde  ;  David's  powder ;  Pode- 
chard's  powder ;  mixture  of  sulphate  of  copper  and  plaster ; 
cupric  steatite  (a  bluish-white,  unctuous  powder,  composed  of 
steatite  and  sulphate  of  copper)  ;  and  sulphatine  (a  secret  mix- 
ture of  sulphur,  lime,  sulphate  of  copper,  and  plaster)."  Then 
follows  a  "table  showing  results  of  experiments  of  Millardet 
and  David  with  mildew  remedies  in  France  in  1886." 

A  letter  from  M.  G.  Foex,  of  Montpellier,  France,  contains  an 
account  of  a  meeting  of  the  International  Congress  held  in 
Florence,  Italy,  during  October.  It  says  that  the  copper  salts  were 
considered  most  valuable,  and  the  formulas  recommended  were 
those  of  the  Bordeaux  mixture  (the  copper  mixture  of  Gironde, 
page  27) ;  eau  celeste,  Audoynaud  process  (page  30)  ;  and  sul- 
phated  sulphur.  In  regard  to  the  last  substance  the  letter  says 
that  "M.  Theophile  Skawinski,  at  Chateau  Laujac,  in  Gironde, 
and  M.  D.  Cavazza,  director  of  the  school  of  viticulture  at  Alba 
(Piedmont),  have  used  successfully  mixtures  of  pulverized  sul- 
phur with  8  to  10  per  cent  of  sulphate  of  copper  finely  tritu- 
rated." According  to  an  official  report  of  the  meetings  held  in 
Florence,  the  conclusions  in  respect  to  the  remedies  for  the 
mildew  "were  :  (1)  That  gaseous  remedies  applied  against  the 
peronospora  have  not  given  useful  results;  (2)  that  among 
the  remedies  in  the  form  of  powder  thus  far  tried  the  most  eifi- 

i  Ann.  Sept.  U.  S.  Com.  of  Agric.t  1886,  95-138. 


The  Recommendations  of  1886.  97 

cacious  are  those  in  which  sulphate  of  copper  is  used ;  (3)  that 
the  mixture  of  lime  and  ashes,  and  of  lime  and  sulphur,  have 
not  as  yet  given  results  sufficiently  satisfactory  to  enable  us  to 
recommend  their  use ;  (4)  among  the  liquid  remedies,  the  milk 
of  lime  prepared  so  as  to  make  it  convenient  for  application, 
has  proven  quite  satisfactory ;  however,  its  use  from  a  practical 
and  economical  standpoint  encounters  in  many  places  serious 
difficulties  ;  (5)  that  the  remedies  most  successful  in  the  results 
obtained  are  the  mixed  liquids  or  solutions  containing  sulphate 
of  copper." 

This  portion  of  the  report  closes  with  an  article  on  Ska- 
winski's  powder  as  a  fungicide,  giving  its  history,  composition, 
and  use.  On  the  pages  which  follow  are  described  several 
fungi  found  upon  the  grape  and  also  some  occurring  upon  other 
plants.  Among  the  latter  may  be  found  an  account  of  the  cel- 
ery leaf-blight  which  is  of  interest  here  on  account  of  a  remedy 
which  is  mentioned  for  its  prevention:  "I  would  hesitate  to 
recommend  the  application  of  solutions  containing  the  salts  of 
copper  on  this  vegetable,  for  hygienic  reasons.  A  solution  of 
penta-sulphuret  of  potassium,  or  liver  of  sulphur,  1  to  2  ounces 
to  a  gallon  of  water,  sprayed  upon  the  plants  at  the  first  appear- 
ance of  the  blight,  may  arrest  its  progress.  This  preparation 
deserves  a  trial  in  this  case."  The  use  of  this  substance  was 
probably  suggested  by  the  English  papers,  which  at  this  time 
contained  many  accounts  of  its  value  for  the  control  of  certain 
fungous  diseases. 

Remedies  for  the  orange-leaf  scab  are  also  suggested,  three 
of  the  preparations  named  being,  "  a  solution  of  bisulphide  of 
potassium,  one-half  ounce  to  a  gallon  of  water ;  the  Grison 
liquid  .  .  .  ;  to  10  gallons  of  strong  soap-suds  add  about  a 
pound  of  glycerine  and  one-half  pint  of  carbolic  acid." 

Regarding  the  treatment  of  potato  rot,  only  suggestions  are 
made.  A  trial  of  Podechard's  powder,  and  of  David's  powder, 
are  recommended. 

The  curing  of  pear  blight  is  looked  upon  as  an  almost 
hopeless  task,  and  unfortunately  we  are  now  little  nearer  the 
solution  of  the  problem  than  at  that  time.  The  report  says 
that  "spraying  offers  little  hope  of  success.  .  .  .  An  experi- 
ment tried  during  last  season  in  spraying  with  a  solution  of 
hyposulphite  of  soda,  applied  several  times  during  the  period 


98  The  Spraying  of  Plants. 

of   expansion  of    the  buds,  gave  no  evidence    of   beneficial 
effects." 

Although  the  Department  of  Agriculture  was  taking  by  far 
the  most  active  part  in  advancing  the  cause  of  the  treatment  of 
fungous  diseases,  the  work  was  not  entirely  confined  to  it.  Early 
in  1886  there  is  recorded1  an  account  of  the  Italian  practice 
of  sprinkling  lime  upon  grape  foliage.  The  remedy  consists 
"  simply  of  a  lime  wash  made  of  5  pounds  fresh  lime  slaked  with 
24  gallons  of  water.  The  vines  are  sprinkled  abundantly  with 
this  wash  from  the  middle  of  May  to  the  middle  of  August,  the 
application  being  repeated  five  or  six  times  in  all." 

Goff  continued  his  experiments  in  the  use  of  the  hyposul- 
phite of  soda,  applying  it,  in  1886,  upon  apples  and  pears.  His 
work  of  the  preceding  year  was  verified  in  the  case  of  the 
apple,  but  the  results  from  pear  trees  were  less  striking,  only  a 
slight  difference  occurring  in  favor  of  the  sprayed  half.  The 
material  was  also  applied  to  pears  for  the  blight,  with  entirely 
negative  results.2 

During  the  spring  of  1886,  "  B.  F.  J."  wrote  an  account  which, 
at  present,  appears  like  a  prophecy ;  for  it  has  taken  scientists 
several  years  to  learn  the  fact  which  at  that  time  was  not 
known  to  exist.  The  writer,  after  speaking  of  the  use  of  a  1  per 
cent  solution  of  blue  stone,  and  of  a  10  per  cent  solution  with 
lime  enough  to  make  a  thin  paste,  for  the  control  of  grape  dis- 
eases, reasons  that  the  copper  sulphate  solutions  should  be  ap- 
plied to  potatoes  "  threatened  with  mildew  or  rot.  .  .  .  But  if, 
in  the  event  of  the  appearance  of  the  Colorado  beetle,  Paris 
green  (arsenite  of  copper)  extended  in  50  times  its  bulk  of  fine, 
ground  land  plaster  be  applied  to  potato  vines  as  often  as 
needed  to  destroy  the  insects,  old  and  young,  it  will  be  worth 
the  while  to  ascertain  if  mildew  makes  its  appearance  in  fields 
so  treated.  It  is  believed  by  the  writer  that  little  or  nothing 
will  be  seen  of  mildew  or  rot  under  such  circumstances,  and  if, 
after  the  bugs  have  disappeared,  the  Paris  green  and  plaster  are 
continued,  the  vines  will  resist  to  the  end."  8 

Whether  the  above  was  founded  on  experience  or  not,  it  does 

1  Country  Gentleman,  1886,  Feb.  4,  88. 

«  Ann.  Kept.  N.  Y.  State  Agric.  Exp.  Sta.  1886,  174. 

»  Country  Gentleman,  1886,  May  27,  405. 


Spraying  in  1887.  99 

not  alter  the  fact  that,  even  at  this  time,  Paris  green  was  believed 
to  have  some  value  as  a  fungicide,  and  this  is  probably  the  first 
statement  of  a  fact  which  was  not  generally  conceded  until  defi- 
nite experiments  made  by  trained  men  had  established  its  truth. 
Such  are  the  most  important  events  of  the  year  1886.  The 
main  feature  of  the  work  was  the  spreading  of  information,  and 
the  recommending  of  lines  of  treatment  to  be  followed.  Little 
actual  work  was  done. 

The  work  of  1887  was  of  the  same  nature,  for  the  results  of 
scarcely  an  experiment  made  in  this  country  were  published. 
Each  one  appeared  to  wait  for  someone  else  to  try  the  reme- 
dies, so  that  there  might  be  no  doubt  about  the  successful  issue 
of  later  experiments.  The  United  States  Department  of  Agri- 
culture apparently  had  no  plantations  in  which  to  work,  for, 
in  the  annual  report  of  the  chief  of  the  Section  of  Vegetable 
Pathology,  more  recommendations  appear  than  do  the  results 
of  actual  field  tests.  The  results  of  the  French  experiments  are 
still  freely  drawn  upon,  and  they  form  the  basis  of  the  recom- 
mendations. Most  of  the  work  done  in  this  country  was  under 
the  direction  of  the  Department  of  Agriculture,  which  is  deserv- 
ing of  praise  for  thus  bearing  the  brunt  of  a  movement  which, 
with  characteristic  conservatism,  has  not  been  immediately 
adopted  by  the  bulk  of  the  agricultural  population. 

Circular  No.  3  of  the  Section  of  Vegetable  Pathology  appeared 
in  April,  1887.  Its  subject  was  the  "  Treatment  of  the  Downy 
Mildew  and  Black  Rot  of  the  Grape."  The  value  of  copper 
sulphate  was  placed  above  that  of  all  compounds  in  which 
no  copper  appeared,  and  formulas  were  given  for  the  manufac- 
ture of  the  following :  the  simple  solution  of  sulphate  of  copper, 
1  pound  of  the  salt  being  dissolved  in  25  gallons  of  water ;  eau 
celeste  (Audoynaud  process)  ;  copper  mixture  of  Gironde,  or 
Bordeaux  mixture,  16  pounds  sulphate  of  copper,  30  pounds  of 
lime,  28  gallons  of  water,  this  being  a  more  dilute  mixture  than 
that  recommended  in  1886 ;  and  it  is  also  stated  that  "  some 
have  reduced  the  ingredients  to  2  pounds  of  sulphate  of  copper, 
and  2  pounds  of  lime  to  22  gallons  of  water,  and  have  obtained 
good  results."  Directions  are  also  given  for  the  manufacture 
of  David's  powder,  and  of  sulphatine,  the  directions  for  the 
latter  being  to  "mix  2£  pounds  of  anhydrous  sulphate  of 


100  The  Spraying  of  Plants. 

copper  with  15  pounds  of  triturated  sulphur,  and  10  pounds 
of  air-slaked  lime." 

Circular  No.  4  appeared  in  July ;  it  was  entitled  "  Treatment 
of  the  Potato  and  Tomato  for  the  Blight  and  the  Rot."  Among 
the  formulas  given,  only  two  require  notice.  That  for  the  Bor- 
deaux mixture  produced  a  still  more  dilute  preparation.  The 
directions  were  to  "  dissolve  4  pounds  of  sulphate  of  copper  in 
16  gallons  of  water ;  in  another  vessel  slake  4  pounds  of  lime 
in  6  gallons  of  water."  This  was  a  decided  improvement  on 
the  formula  published  during  the  preceding  April.  Among 
the  dry  applications  is  found  a  "  Blight  powder  " ;  this  was 
made  by  mixing  "  3  pounds  of  anhydrous  sulphate  of  copper 
with  97  pounds  flowers  of  sulphur."  It  has  not  come  into 
general  use. 

The  annual  report  of  the  Section  of  Vegetable  Pathology  for 
1887 l  is  full  of  suggestion  and  encouragement.  The  white  rot 
and  the  bitter  rot  of  grapes  are  described,  they  having  been 
identified  in  this  country  for  the  first  time.  Copper  compounds 
are  recommended  for  their  treatment.  New  formulas  are  intro- 
duced, as  the  old  ones  had  not  given  satisfaction  in  all  cases. 
The  manufacture  of  eau  celeste  is  described  as  follows : 

"In  2  gallons  of  hot  water,  dissolve  1  pound  sulphate  of 
copper ;  in  another  vessel  dissolve  2  pounds  ordinary  carbonate 
of  soda ;  mix  the  two  solutions,  and,  when  all  reaction  has 
ceased,  add  1|  pints  of  liquid  ammonia ;  when  desired  for  use, 
dilute  to  22  gallons." 2  This  preparation  has  become  better 
known  under  the  name  "  modified  eau  celeste." 

To  prevent  injury  to  the  young  shoots,  the  following  solution 
is  recommended :  u  Dissolve  1  pound  sulphate  of  copper  in  a 
gallon  of  hot  water,  to  this  solution  add  liquid  ammonia,  a  little 
at  a  time,  until  all  the  copper  is  precipitated ;  the  liquid  is  then 
turbid  and  blue  in  color.  Add  2  or  3  gallons  of  water,  and  let 
stand  to  settle.  Then  pour  off  the  clear  liquid  which  contains 
sulphate  of  ammonia  —  the  compound  which  causes  the  burn- 
ing of  the  leaves.  Then  pour  upon  the  precipitate  left  in  the 
vessel  just  enough  liquid  ammonia  to  dissolve  it.  ...  When 
required  for  use  dilute  to  22  gallons."  3 

1  Ann.  Bept.  U.  S.  Com.  of  Agric.  188T,  323-397. 

2  Formula  of  M.  Masson,  Progres  Agricole,  1887,  July. 
»  Progres  Agricole  et  Viticole,  1888,  April  29. 


Spraying  in 


The  last  formula  of  the  year  for  making  the  Bordeaux  mix- 
ture is  introduced  by  a  statement  that  "  considerable  latitude 
is  allowed  in  quantity  of  lime  and  copper  sulphate  in  the  Bor- 
deaux mixture,  but  the  amount  of  the  latter  ought  not  to  fall 
below  4  per  cent.  The  most  recently  recommended  formula  for 
the  preparation  of  this  compound  is  4  pounds  of  sulphate  of 
copper,  2  pounds  lime,  25  gallons  water."  1 

The  report  also  contains  a  description  of  the  strawberry- 
leaf  blight  with  directions  for  treatment.  Regarding  the  lat- 
ter point,  the  work  done  in  the  laboratory  showed  "  that  these 
conidia  will  not  germinate  in  very  dilute  solutions  of  hyposul- 
phite of  soda  or  sulphate  of  copper.  It  is  a  simple  matter  to 
apply  similar  solutions  to  the  plants  in  the  field,  where  it  is  only 
reasonable  to  suppose  they  will  have  a  like  action  on  the  repro- 
ductive bodies  in  question."  The  hyposulphite  of  soda  solution 
was  made  by  dissolving  1  pound  of  the  salt  in  10  gallons  of 
water.  One  form  of  copper  solution,  recommended  for  the  first 
time  in  America,  was  thus  prepared:  "In  1  quart  of  liquid 
ammonia  dissolve  3  ounces  of  carbonate  of  copper,  then  dilute 
to  20  gallons."  This  was  here  called  the  ammoniacal  carbonate 
of  copper. 

Regarding  the  treatment  of  apples  for  the  scab,  are  the 
following  statements  :  "  Experiments  already  made  with  the 
sulphate  of  copper  solutions  indicate  that  they  will,  when  prop- 
erly applied,  at  once  check  the  scab.  .  .  .  The  following  course 
of  treatment  is  suggested  : 

"  1.  In  early  spring,  before  the  buds  have  commenced  to 
expand,  spray  the  trees  thoroughly  with  a  solution  of  sulphate 
of  iron,  using  4  pounds  of  iron  sulphate  to  4  gallons  of  water. 

"  2.  As  soon  as  the  fruit  has  set,  apply  the  Bordeaux  mix- 
ture or  one  of  the  modified  preparations  of  eau  celeste. 

"  3.  If  the  weather  should  be  such  as  to  favor  the  develop- 
ment of  the  scab  fungus,  a  third  application  should  be  made 
two  or  three  weeks  after  the  second,  using  the  same  materials." 

The  chloride  of  iron  or  some  other  fungicide  is  suggested  for 
preventing  the  rust  of  beets.  The  anthracnose  of  the  raspberry 
and  the  blackberry  is  supposed  to  be  amenable  to  treatment  as 
well  as  that  of  the  grape,  and  the  same  practice  of  washing  the 

1  Viala  and  Ferrouillat,  "  Manuel  pratique  pour  le  Traitement  des  Maladies  de  la 
Yigne,"  second  edition,  1888,  27. 


j  ;  fJib:  ^paying  of  Plants. 

dormant  canes  with  the  sulphate  of  iron  solution  is  recom- 
mended. When  the  plants  are  in  leaf,  the  Bordeaux  mixture 
should  be  substituted  for  the  solution.  In  treating  beans  for  the 
anthracnose,  solutions  of  the  liver  of  sulphur  are  most  prized, 
as  less  danger  is  connected  with  their  use.  Treatments  of  the 
following  plants  for  fungous  diseases  are  also  recommended, 
the  copper  compounds  being  particularly  advised :  catalpa,  for 
leaf  spot ;  rose,  for  black  spot ;  rose  rust,  for  which  the  chloride 
of  iron  is  preferred,  it  having  been  reported  as  of  value  in  the 
treatment  of  a  coffee  disease ;  and  gooseberry,  for  mildew.  The 
Grison  liquid  is  also  mentioned. 

The  work  of  controlling  plant  diseases,  other  than  that 
planned  by  the  United  States  Department  of  Agriculture,  was 
conspicuous  by  its  absence.  The  agricultural  journals  occa- 
sionally copied  parts  of  the  government  reports,  or  made  recom- 
mendations, but  scarcely  a  record  of  individual  efforts  can  be 
found.  The  various  State  stations  already  established  were 
also  inert,  with  a  single  exception.  Goff  was  continuing  the 
work  he  had  begun  in  1885,  and  this  year,  1887,  treated  apple 
trees  with  the  hyposulphite  of  soda,  and  with  the  Audoynaud's 
eau  celeste.  The  former  proved  as  satisfactory  as  in  preceding 
years.  The  latter,  however,  was  too  strong  for  the  foliage,  one 
application  causing  decidedly  injurious  effects.  The  fruits  on 
portions  that  were  sprayed  three  times  dropped  from  the  trees 
before  maturity.1  These  experiments  may  have  formed  the 
basis  of  the  remarks  in  the  report  of  the  Section  of  Vegetable 
Pathology  regarding  the  injury  caused  by  eau  celeste,  for  I  can 
find  no  other  account  of  the  use  of  this  fungicide  during  the 
year  upon  apples.  Arthur  also  reports  marked  success  in  the 
use  of  the  sulphide  of  potassium  in  the  treatment  of  gooseberry 
mildew,  the  solution  being  used  at  the  rate  of  one-half  ounce 
of  the  chemical  to  one  gallon  of  water.2 

After  the  establishment  of  the  government  experiment  sta- 
tions, most  of  which  were  organized  in  1888,  the  bulk  of  the 
work  done  to  advance  the  methods  of  controlling  plant  diseases 
was  carried  on  by  the  stations  and  by  the  Department  of  Agri- 
culture at  Washington,  the  work  of  the  Section  of  Vegetable 
Pathology  being  especially  thorough.  The  published  reports 

i  Ann.  Rep.  N.  Y.  State  Agric.  Exp.  Sta.  188T,  99-101.  *  Ibid.  348. 


Spraying  in  1888  and  1889.      103 

of  these  experiments  have  taken  the  lead  in  the  endeavors  to 
overcome  fungi  affecting  cultivated  plants,  and  they  are  a  record 
in  which  may  be  found  the  gradually  lengthening  list  of  plant 
diseases  which  have  succumbed.  It  is  impossible  to  give  the 
details  of  the  enormous  amount  of  the  work  done  each  year, 
so  only  the  more  important  contributions  will  be  noted. 

A  bulletin  of  particular  value  to  grape  growers  was  issued  by 
the  Agricultural  Department  in  1888.  It  records  the  results  of 
many  experiments  made  in  1887  in  the  use  of  the  several  for- 
mulas published  in  Circular  No.  3  of  the  Section  of  Vegetable 
Pathology.  The  downy  mildew  and  the  black  rot  are  the  two 
diseases  controlled.  The  Bordeaux  mixture  proved  to  be  the 
most  satisfactory  remedy.1 

The  report  of  the  Section  of  Vegetable  Pathology  for  1888,2 
Professor  B.  T.  Galloway  having  been  appointed  chief  of  the 
Section  in  November,  contains  a  long  list  of  diseases  which 
were  studied  and  treated.  Mention  is  made  of  various  diseases 
of  the  grape ;  the  downy  mildew  of  potatoes  ;  tomato  black-rot, 
and  a  form  of  blight ;  brown  rot  and  powdery  mildew  of  cher- 
ries ;  leaf  blight  and  cracking  of  the  pear ;  rose-leaf  spot ;  plum 
pockets ;  apple  rusts ;  leaf  spot  of  maples ;  a  sycamore  disease ; 
cotton  wood-leaf  rust ;  peach  yellows ;  and  notes  on  celery-leaf 
blight.  This  list  well  represents  the  energy  which  was  displayed 
in  America  in  combating  all  fungous  diseases  as  soon  as  the 
proper  methods  were  supplied.  The  study  of  fungi  was  vigor- 
ously carried  on  by  many  investigators,  and  a  firm  basis  for 
experimental  work  was  thus  established. 

Early  in  1889  the  same  department  published  a  bulletin  in 
which  several  plant  diseases  and  the  methods  of  their  treatment 
are  mentioned.3  Applications  of  the  sulphide  of  potassium  so- 
lution, or  of  modified  eau  celeste,  were  advised  for  the  treatment 
of  the  apple  scab,  and  the  same  remedies,  or  other  fungicides 
then  known,  were  named  in  connection  with  apple  rust  and 
bitter  rot.  The  black  rot  of  grapes  was  successfully  treated  in 
1888  by  Colonel  A.  W.  Pearson,  Vineland,  N.J.,  who  made 
experiments  under  the  direction  of  the  commissioner  of  agri- 

1  Scribner,  U.  8.  Dept.  Agric.  Bol.  Div.  Bull.  5. 

*  Ann.  Rept.  U.  S.  Com.  Agric.  1888,  325-404. 

3  Galloway,  U.  S.  Dept.  Agric.  Bot.  Div.  Bull.  8,  45-67. 


104  The  Spraying  of  Plants. 

culture.  The  Bordeaux  mixture  proved  to  be  most  satisfactory, 
and  the  following  formula  for  its  manufacture  is  given  : 

"Dissolve  6  pounds  of  sulphate  of  copper  in  16  gallons  of 
water ;  in  another  vessel  slake  4  pounds  of  lime  in  6  gallons  of 
water."  The  two  liquids  were  then  slowly  mixed  and  the 
preparation  was  ready  for  use.  This  formula  is  the  one  which 
at  first  was  most  widely  recommended. 

The  methods  of  treating  the  rust  of  melons  consisted  in  the 
use  of  a  carefully  prepared  eau  celeste,  only  enough  ammonia 
being  added  to  precipitate  the  copper.  The  liquid  was  then 
poured  off,  and  ammonia  added  to  the  copper  sediment  remain- 
ing in  the  bottom  of  the  vessel  until  all  the  copper  was  again 
dissolved.  One  pound  of  the  sulphate  of  copper  so  treated  was 
sufficient  for  twenty-two  gallons  of  water.  Hyposulphite  of 
soda  and  also  the  sulphide  of  potassium  were  suggested  for  the 
prevention  of  bean  anthracnose. 

Bulletin  11  of  the  Section  of  Vegetable  Pathology  gives  an 
account  of  some  of  the  work  done  in  the  treatment  of  plant 
diseases  during  the  year  1889.  In  addition  to  the  various 
diseases  which  had  already  received  attention,  the  following 
are  named :  leaf  blight  of  the  pear  and  of  the  quince ;  rusts  of 
the  peach,  plum,  quince,  and  blackberry ;  leaf  blight  of  the 
strawberry  and  of  the  blackberry ;  and  the  rot  and  the  blight  of 
tomatoes.  In  the  annual  report  of  the  Section1  additional 
mention  is  made  of  the  treatment  of  several  apple  diseases, 
including  the  important  experiments  of  Taft,  Goff,  and  Hatch 
on  the  apple-scab  fungus.  The  account  of  the  treatment  of 
nursery  stock  for  the  powdery  mildew  is  also  interesting. 
Pear  stock  was  treated  for  the  leaf  blight,  and  these  experi- 
ments may  be  considered  as  being  the  first  directed  towards  the 
protection  of  nursery  stock.  The  nurseries  of  Franklin  Davis 
&  Co.,  situated  twenty  miles  north  of  Washington,  were  used  in 
these  experiments.  The  following  year  the  first  applications 
on  cherry  stocks  were  made,  the  disease  treated  being  that 
commonly  known  as  leaf  blight.  In  later  years  the  treatment 
of  nursery  stock  became  one  of  the  leading  features  of  the 
work  of  the  Section. 

It  was  during  1889  that  the  government  experiment  stations 
began  to  report  the  results  of  work  in  the  treatment  of  plant 
»  Ann.  Kept.  U.  S.  Com.  Agric.  1889,  397-432. 


Combinations  of  Insecticides  and  Fungicides.     105 

diseases.  In  October,  Xeale  published1  an  account  of  work 
done  in  Delaware  vineyards.  The  Bordeaux  mixture  was  used 
with  an  estimated  saving  of  $65.25  per  acre.  Stained  fruit 
was  cleaned  by  placing  it  in  wire  baskets  which  were  dipped 
in  diluted  vinegar.  The  fruit  was  allowed  to  remain  here  a 
few  moments,  and  then  dried  on  wire  frames. 

An  important  article  written  by  Weed  appeared  the  following 
month.2  He  conceived  the  idea  of  applying  insecticides  and 
fungicides  together,  and  the  statement  is  made  that  "a  con- 
siderable number  of  experiments  with  this  end  in  view  have 
been  carried  on  during  the  season  with  very  satisfactoiy 
results."  One  of  these  experiments  was  designed  to  control 
the  brown  rot  of  stone  fruits.  A  plum  orchard  was  treated 
for  this  disease  as  follows :  "  We  sprayed  the  trees  early  in 
April  (April  16),  before  the  leaves  came  out,  with  a  simple 
solution  of  copper  sulphate;  and  twice  during  May  (loth  and 
25th),  the  first  with  London  purple  alone,  the  second  with  a 
combination  of  London  purple  and  the  Bordeaux  mixture, 
which  treatment  was  repeated  June  1.  No  further  applica- 
tions were  made,  except  to  one  tree,  which  was  sprayed  with 
the  Bordeaux  mixture  July  16."  Fairly  satisfactory  results 
were  obtained  from  the  applications. 

The  Bordeaux  mixture  was  also  applied  to  apple  trees  for  the 
prevention  of  the  scab,  but  the  results  were  decidedly  against 
the  use  of  this  fungicide  for  the  treatment  of  the  disease,  a 
result  which,  it  is  scarcely  necessary  to  say,  has  not  been 
verified  in  late  years.  The  black  rot  of  the  grape,  and  the 
quince-leaf  spot,  were  more  successfully  controlled  by  the  same 
remedy. 

Maynard  tried  a  combination  of  Paris  green  and  a  solution  of 
copper  sulphate  upon  potatoes.  The  growth  of  foliage  was 
checked,  but  the  blight  was  not  so  serious  upon  the  treated 
as  upon  the  untreated  portions.3 

At  the  time  that  Gillette  was  experimenting  with  mixtures 
of  the  arsenites  and  lime  (see  page  76),  he  also  used  the  Bor- 
deaux mixture  in  place  of  pure  lime,  with  such  success  that 

1  Del.  Affric.  Exp.  Sta.  1SS9,  Bull.  6. 

2  Ohio  Agric.  Escp.  Sta.  second  series,  Vol.  ii.  1SS9,  BulL  7,  186.     See  also 
Agricultural  Science,  Vol.  iii.  18S9,  263. 

s  Jfass.  Hatch  Agric.  Exp.  Sta.  1890,  Jan.  Bull.  7, 12. 


106  The  Spraying  of  Plants. 

the  use  of  the  combination  rapidly  gained  favor.  One  of  the 
conclusions  reached  was  that  "  London  purple  (Paris  green  and 
white  arsenic  have  not  yet  been  tried)  can  be  used  at  least  eight 
or  ten  times  as  strong  without  injury  to  foliage  if  applied  in 
common  Bordeaux  mixture  instead  of  water."  Later  experi- 
ments have  shown  that  Paris  green  can  be  applied  in  the  same 
manner  with  greater  safety  than  when  pure  water  is  used. 

Although  the  smuts  of  grain  are  not  best  treated  by  spraying, 
still  these  diseases  are  sufficiently  connected  with  the  subject  in 
hand  to  allow  the  mention  of  some  work  done  by  Kellerman 
and  Swingle.1  In  1889  the  work  was  mainly  verifying  the 
methods  proposed  by  Professor  Jensen,  of  Copenhagen,  Den- 
mark, for  the  treatment  of  the  various  grain  smuts.  The 
following  year  fifty-one  methods  for  treating  the  stinking  smut 
of  wheat  were  tried.  "  Of  all  the  treatments  tested,  the  Jensen, 
or  hot-water  method,  is  probably  the  best  for  general  use, 
although  in  our  experiments  it  did  not  prevent  all  the  smut" 
(see  Part  II.  under  OATS). 

Halsted  published  a  report  in  1889  which  proved  to  be  the 
beginning  of  an  important  series.2  This  first  publication  con- 
tained notes  on  diseases  of  the  potato,  grape,  cranberry,  cucum- 
ber, sweet  potato,  and  lilac,  those  of  the  cranberry  having 
already  been  mentioned  in  Bulletin  64  of  the  station.  The 
reader  is  referred  to  later  reports  by  the  same  investigator  for 
the  descriptions  and  methods  of  treatment  of  a  great  many  dis- 
eases of  plants  cultivated  out  of  doors,  and  also  of  those  grown 
under  glass.  The  reports  are  especially  rich  in  the  accounts  of 
diseases  affecting  greenhouse  plants,  and  those  commonly  grown 
by  florists. 

During  1890,  Maynard  continued  his  work  on  the  combina- 
tions of  insecticides  and  fungicides.3  He  used  the  ammoniacal 
carbonate  of  copper  together  with  Paris  green.  The  foliage 
was  in  all  cases  seriously  injured,  and  the  fungicide  appeared  to 
lose  its- value  when  used  in  this  manner.  Later  experiments 
have  generally  agreed  with  this  result,  and  such  a  combi- 
nation has  not  been  used  in  common  practice.  Kerosene  had 

1  Kansas  Agric.  Exp.  Sta.  1889,  Oct.  Bull.  8,  and  1890,  Aug.  Bull.  12. 

2  Ann.  Sept.  IT.  J.  Agric.  Exp.  Sta.  1889,  221-239. 

»  Mass.  Hatch  Agric.  Exp.  Sta.  1891,  Jan.  Bull.  11, 18. 


Spraying  in  1890.  107 

been  tried  for  the  destruction  of  the  black  knot  of  plums,  but 
injury  was  liable  to  be  done  to  the  small  growths,  for  the  oil 
spread  to  other  places  than  those  on  which  it  had  been  applied. 
The  recommendation  is  therefore  made  that  the  oil  be  mixed 
with  some  pigment  to  form  a  thin  paste,  and  this  is  then  to  be 
spread  over  the  newly  forming  knots.  Very  satisfactory  results 
had  followed  the  use  of  the  remedy,  the  knots  being  destroyed 
without  injury  to  the  sound  tissues.  The  applications  were 
made  with  a  brush. 

The  Agricultural  Department  at  Washington  was  conducting 
work  in  the  treatment  of  diseases  of  the  grape,  apple,  pear, 
quince,  raspberry,  hollyhock,  and  cotton.  Comparative  tests  of 
fungicides  were  also  made,  and  a  new  one  known  as  mixture 
No.  5  was  considered  as  having  special  merit.  "  It  consists  of 
equal  parts  of  ammoniated  sulphate  of  copper  [see  page  117]  and 
carbonate  of  ammonia  thoroughly  mixed  and  put  up  in  air-tight 
tin  cans."1  It  was  used  at  the  rate  of  12  ounces  in  22  gallons 
of  water,  but  this  proved  injurious  to  the  foliage  of  cherry, 
peach,  blackberry,  and  young  grape  shoots. 

Chester,  of  the  Delaware  station,  made  some  important 
experiments  in  the  treatment  of  grape  diseases.2  The  fun- 
gicides tested  were  the  "  ammoniated  carbonate  of  copper,"  or 
the  ammoniacal  solution  of  copper  carbonate ;  the  carbonate  of 
copper  and  the  carbonate  of  ammonia  mixture,  a  compound 
first  used  by  this  station,  and  prepared  by  mixing  together  3 
ounces  of  carbonate  of  copper  and  1  pound  of  pulverized  car- 
bonate of  ammonia,  and  then  dissolving  in  2  quarts  of  hot 
water,  after  which  the  solution  can  be  diluted  to  50  gallons ; 
the  precipitated  carbonate  of  copper ;  the  Bordeaux  mixture ; 
modified  eau  celeste ;  and  mixture  No.  5,  of  the  United  States 
Department  of  Agriculture.  While  all  the  conclusions  drawn 
from  the  work  have  not  been  fully  substantiated  in  after  years, 
the  publication  did  much  to  demonstrate  the  practicability  and 
financial  success  of  proper  applications  of  fungicides.  The  Bor- 
deaux mixture  was  recommended  as  being  perhaps  the  best  to 
use  early  in  the  season,  but  when  danger  of  staining  the  fruit 
arose,  the  use  of  the  carbonate  of  copper  and  carbonate  of 
ammonia  solution,  or  of  the  modified  eau  celeste,  was  recom- 

1  Galloway,  Ann.  Eept.  U.  S.  Com.  Agric.  1890,  402.    See  also  p.  160. 
*  Del.  Agric.  Exp.  Sta.  1890,  Bull.  10. 


108  The  Spraying  of  Plants. 

mended.  The  precipitated  carbonate  of  copper  was  thought 
to  be  valuable  as  a  fungicide,  but  it  has  since  fallen  from 
favor. 

Professor  L.  R.  Jones,  of  Vermont,  began  work  upon  potato 
diseases  in  1890,  and  since  that  time  valuable  reports  have  been 
published  by  him  regarding  the  various  diseases  of  this  crop. 
In  the  annual  report  of  the  station  for  that  year  may  be  found 
a  condensed  account  of  the  work  upon  potatoes  as  well  as  upon 
the  diseases  of  other  plants.1 

In  Galloway's  report  for  the  year 2  1890  is  the  statement : 
"  In  treating  the  disease  [leaf  blight  of  pear,  cherry,  and  straw- 
berry] the  present  season,  the  best  results  were  obtained  from 
the  use  of  the  ammoniacal  copper  carbonate  and  the  Bordeaux 
mixture.  As  far  as  the  efficacy  of  the  two  fungicides  is  con- 
cerned, there  is  little  choice.  The  ease  with  which  the  ammo- 
niacal solution  is  prepared  and  applied,  however,  makes  it  more 
desirable  in  the  end."  These  two  fungicides  were  at  the  time 
generally  considered  to  be  the  best. 

In  1891,  Galloway  published  an  account  of  the  use  of  Bordeaux 
mixture  made  of  different  strengths,  and  the  results  obtained 
showed  that  for  grape  diseases  it  was  not  necessary  to  use  as 
much  copper  sulphate  and  lime  as  the  formula  given  in  Circular 
4  of  the  Section  of  Vegetable  Pathology  called  for.  "  There 
was  little  difference  between  the  plats  treated  early  with  full- 
strength  and  those  treated  in  the  same  way  with  the  half- 
strength  mixture."  3  The  "  half-strength  "  was  made  by  using 
one-half  the  amount  of  materials  called  for  by  what  has  later 
been  termed  the  "  standard "  formula  mentioned  in  Circu- 
lar 4,  the  amount  of  water  used  remaining  the  same.  The 
half-strength  or  "  normal "  formula  was  soon  very  generally 
adopted. 

Goff  in  1891  established  the  fact  that  Paris  green  possesses 
marked  fungicidal  value,  especially  during  dry  seasons.4  Later 
experiments  made  by  Lodeman  have  shown  that  the  poison  is 

1  Ann.  Kept.  Vt.  Agric.  Exp.  Sta.  1890,  129-144.    See  also  Bull.  24  of  the  same 
station  for  more  detailed  descriptions. 

2  Ann.  Rept.  U.  S.  Com.  Agric.  1890,  393^08. 
»  Ann.  Rept.  U.  S.  Com.  Agric.  1891,  367. 

*  Ibid.  364 ;  and  Ann.  Rept.  Wis.  Agric.  Exp.  Sta.  1891-92,  264. 


Spraying  in  1891.  109 

of  value  in  wet  seasons  as  well ; l  and  it  is  at  present  considered 
as  possessing  more  value  to  the  apple  grower  than  any  other 
single  compound  which  he  has  at  his  command  for  checking 
fungous  and  insect  enemies. 

It  is  singular  that  while  our  most  reliable  insecticide,  Paris 
green,  is  found  to  possess  value  as  a  fungicide,  the  Bordeaux 
mixture,  which  is  probably  our  best  fungicide,  should  possess 
a  marked  insecticidal  value.  In  some  notes  which  appeared  in 
the  Journal  of  Mycology  (Vol.  vii.  27),  Hatch,  of  Ithaca,  Wis., 
says  that  in  treating  potatoes  it  was  noticed  that  plants  sprayed 
with  the  Bordeaux  mixture  suffered  less  from  insects  than 
those  used  as  checks,  and  "it  would  thus  appear  that  where 
the  mixture  is  used  for  rot  and  blight  it  may  also  be  efficient 
as  an  insecticide."  Professor  Jones,  of  Vermont,  gave  still  more 
positive  information  of  the  same  nature  at  the  Brooklyn  meet- 
ing of  the  Society  for  the  Promotion  of  Agricultural  Science,2 
although  his  remarks  applied  particularly  to  injuries  from  the 
flea  beetle.  Beets  were  protected  in  a  similar  manner.  Gallo- 
way writes  me  as  follows  regarding  the  experience  of  the 
government  experimenters :  "  We  also  had  a  striking  case  a  few 
years  ago  in  treating  a  large  vineyard.  The  leaves  on  the 
plants  of  our  check  plats  were  all  badly  eaten  by  the  grape-vine 
fidia,  while  those  adjacent,  sprayed  with  Bordeaux  mixture, 
were  not  touched  at  all."  3 

In  1891  Chester  made  a  comparative  test  of  some  fungicides 
which  at  that  time  seemed  to  be  of  value,  but  which  were  not 
in  general  use.4  Applications  were  made  to  pear  trees,  the  fol- 
lowing formulas  being  used  for  preparing  the  fungicides : 

C.  Copper  carbonate 1  pound. 

Water 25  gallons. 

G.  Copper  sulphate 8  ounces. 

Soda  hyposulphite 14      " 

Water 25  gallons. 

1  Cornell  Agric.  Escp.  Sta.  Bull.  48,  272. 

*  Agricultural  Science,  Vol.  viii.  364-367. 

s  See  Ann.  Rept.  Ky.  Agric.  Exp.  Sta.  1890,  40  (distributed  early  in  1895), 
for  experiments  made  by  Garman  on  tobacco  worms,  grasshoppers,  and  potato 
beetles,  in  1889,  these  being  the  first  of  this  nature  ;  also  Cornell  Agric.  Exp.  Sta. 
Bull.  86,  58,  for  the  prevention  of  insect  injuries  to  apples ;  Ann.  Sept.  Vt.  Agric. 
Exp.  Sta.  1S94,  12,  81,  95  et  seq. 

*  Del.  Agric.  Exp.  Sta.  1892,  Bull.  15,  5. 


110  The  Spraying  of  Plants. 

H.  Johnson's  mixture :  1 

Copper  sulphate 8  ounces 

Ammonium  carbonate I  pound. 

Water 25  gallons. 

I.  Copper  carbonate 8  ounces. 

Ammonium  carbonate 1  pound. 

Water 25  gallons. 

A.  Copper  carbonate 3  ounces. 

Ammonia  26° 1  quart. 

Water 25  gallons. 

B.  Copper  carbonate 3  ounces. 

Ammonium  carbonate 1  pound. 

Hot  water 2  quarts. 

Water  to  dilute  to 25  gallons. 

D.  Copper  sulphate 6  pounds. 

Quicklime 4      " 

Water 25  gallons. 

E.  Copper  sulphate 1  pound. 

Sal-soda 11  pounds. 

Ammonia 1  pint. 

Water 25  gallons. 

After  two  years'  trial  of  the  above,  the  formulas  D,  E,  and  I 
were  shown  to  be  the  most  effective.  D,  or  the  Bordeaux  mix- 
ture, exerted  no  injurious  action  on  the  foliage  nor  on  the 
fruit ;  E,  or  the  modified  eau  celeste,  had  but  slight  action  on 
the  foliage ;  while  preparation  I  had  little  or  no  action  on  foli- 
age or  fruit.  This  really  implies  that  the  Bordeaux  mixture 
was  as  effective  as  any  fungicide  used,  and  that  it  proved  to  be 
the  safest  as  well.  The  only  objection  raised  to  it  was  the 
difficulty  of  making  the  applications.  The  other  preparations 
were  either  of  less  fungicidal  value,  or  they  injured  foliage. 

Since  1892  exhaustive  experiments  have  been  conducted  by 
the  United  States  Department  of  Agriculture  for  the  prevention 
of  rusts  affecting  wheat  and  other  cereals.  In  that  year,  eleven 
preparations  were  applied,  two  being  in  the  form  of  powder; 
the  remainder  were  liquid,  and  were  sprayed  upon  the  plants  or 

1  This  fhngicide  was  so  called  from  the  fact  that  Dr.  S.  W.  Johnson  first  pro- 
posed its  use  in  the  Ann.  Kept,  of  the,  Conn.  Agric.  Exp.  Sta.  1890, 113.  It  never 
came  into  general  use. 


Spraying  in  1892.  Ill 

were  applied  to  the  soil.  The  materials  used  were  the  Bordeaux 
mixture,  the  ammoniacal  solution  of  copper  carbonate,  ferrous 
ferrocyanide  mixture,  copper  borate  mixture,  ferric  chloride 
solution,  ferrous  sulphate  solution,  cupric  ferrocyanide  mixture, 
cupric  hydroxide  mixture,  potassium  sulphide  solution,  flowers 
of  sulphur,  and  sulphosteatite.  Although  these  were  applied 
in  various  ways,  the  results  were  in  no  case  favorable  for  en- 
couraging the  use  of  fungicides  in  controlling  such  diseases,1 
and  later  experiments  have,  on  the  whole,  verified  the  results 
then  obtained.  The  same  report  also  contains  a  list  of  twenty- 
five  different  mixtures  which  were  applied  to  pear  nursery  stock 
at  Geneva,  N.Y.,  the  number  including  various  compounds  of 
copper,  iron,  and  zinc.  The  copper  compounds  proved  to  be 
the  most  efficient  in  preventing  leaf  blight,  and  no  compound 
was  found  which  has  proved  to  be  preferable  to  the  Bordeaux 
mixture. 

One  of  the  most  important  advances  of  the  year  1894  was 
made  by  Bailey.1  In  treating  a  quince  orchard  with  the 
Bordeaux  mixture  it  was  found  that  the  rust  (Rcestelia 
aurantiacci)  "  was  certainly  less  prevalent  in  the  sprayed  por- 
tion of  Colonel  Bowmen's  orchard  [Medina,  N.Y.]  than  in  the 
unsprayed  part." 

Many  valuable  experiments  have  been  made,  and  many  im- 
portant results  obtained,  which  cannot  be  named  in  this  brief 
account  of  the  ever-widening  use  of  insecticides  and  fungicides; 
yet  one  other  disease  is  of  sufficient  importance  to  require 
special  mention.  The  black  knot  of  plums  and  cherries  is  con- 
tinually threatening  the  profitable  cultivation  of  these  fruits, 
and  in  some  localities  the  disease  has  forced  growers  to  aban- 
don their  culture  on  account  of  the  death  of  the  trees. 

Maynard  has  recorded3  an  experiment  in  which  certain  plum 
trees  were  sprayed  with  copper  sulphate  solution  early  in  the 
season,  and  later  with  the  Bordeaux  mixture,  the  last  treatment 
being  made  July  29.  The  conclusion  drawn  from  the  experi- 
ment was  that  "the  number  of  warts  was  very  decidedly  less 
where  treated  with  the  copper  mixture  than  where  untreated, 

1  Galloway,  Ann.  Sept.  U.  S.  Com.  Agric.  1892,  216  et  seq.    Fairchild,  Jour,  of 
Mycology,  Vol.  vii.  No.  8,  240. 

2  Cornell  Agric.  Exp.  Sta.  1894,  Bull.  80,  627. 

3  Mass.  Hatch  Agric.  Exp.  Sta.  1891,  Bull.  11, 19. 


112  The  Spraying  of  Plants. 

.  .  .  and  we  believe  that  the  plum  wart  may  be  held  in  check 
by  the  use  of  this  remedy."  This  note  attracted  but  little 
attention,  and  four  years  later,  when  the  Cornell  station  pub- 
lished a  bulletin x  on  the  same  subject,  scarcely  a  person  appears 
to  have  adopted  the  remedy.  The  Cornell  experiments  were 
carried  on  during  two  seasons,  and  they  showed  conclusively 
that  the  disease  can  be  treated  successfully  and  profitably  by 
the  use  of  the  Bordeaux  mixture. 


II.   IN  CANADA. 

Canada  was  active  in  taking  advantage  of  the  knowledge 
gained  in  the  United  States  and  in  Europe.  The  experiments 
of  Saunders  in  destroying  the  potato  beetle  were  made  soon 
after  the  discovery  of  the  value  of  Paris  green  (see  page  60). 
Through  the  kindness  of  Professor  Craig,  of  Ottawa,  I  have 
been  able  to  collect  the  following  data  regarding  the  early  use 
of  insecticides  and  fungicides  in  the  provinces.  He  writes  that 
"  as  far  as  I  know  G.  W.  Cline,  of  Winona,  Ontario,  and  J.  K. 
McMichael,  of  Waterford,  Ontario,  were  the  pioneers  among 
the  practical  orchardists  in  the  work  of  applying  insecticides." 
In  reply  to  a  letter,  the  last-named  gentleman  kindly  writes  as 
follows :  "  I  commenced  spraying  about  the  spring  of  1883  with 
a  small  force-pump,  using  a  number  of  ingredients,  as  an  experi- 
ment to  destroy  fungi  on  pear  trees.2  In  the  spring  of  1887,  I 
bought  a  large  double-acting  force-pump,  and  sprayed  my  apple 
and  pear  trees  with  a  solution  of  hyposulphite  of  soda,  which 
I  first  used  in  1885  to  destroy  fungi,  and  obtained  fairly  good 
results.  For  canker-worm  and  other  insects  I  used  Paris  green. 
For  a  few  years  I  sprayed  with  the  carbonate  of  copper  to 
destroy  fungi  on  the  leaves  and  fruit  of  apples  and  pears,  but 
recently  the  sulphate  of  copper  has  been  applied  for  the  same 
purpose."  Since  neither  Mr.  McMichael  nor  Professor  Craig 
know  of  any  grower  in  Ontario  who  sprayed  any  earlier  than 
is  stated  in  the  above  letter,  we  may  conclude  that  the  former 
was  the  first,  or  at  least  one  of  the  first,  to  make  such  appli- 
cation in  that  province. 

i  Lodeman,  Cornell  Agric.  Exp.  Sta.  1894,  Bull.  81. 

*  See  Ann,  Kept.  Fruit  Grower*1  Ass'n  of  Ont.  1889,  86.  Mention  is  here 
made  of  the  application  of  hyposulphite  of  soda  in  IbSL 


Spraying  in  Canada.  113 

I  am  also  indebted  to  Mr.  R.  W.  Starr,  of  Wolfville,  Nova 
Scotia,  who  has  taken  the  pains  to  write  so  complete  an  outline 
of  this  branch  of  horticultural  work  in  the  Eastern  section  of 
Canada,  that  the  letter  is  given  below  in  full: 

"I  can  scarcely  give  dates  as  to  when  spraying  was  first 
adopted  in  this  province,  as  the  practice  has  grown  up  from 
small  beginnings  with  the  fine  rose  watering-pot  and  garden- 
syringe,  using  solutions  of  whale-oil  soap,  tobacco,  or  hellebore 
to  destroy  the  currant  and  gooseberry  worm,  and  thrips  on  the 
rose  bushes.  These  methods  wrere  in  use  by  the  late  Hon.  C.  R. 
Prescott  as  early  as  in  the  forties  at  least,  and  I  can  remem- 
ber some  experiments  of  his  with  tobacco  and  the  soap  solution 
to  drive  the  curculio  from  his  plums,  but  this  was  afterwards 
abandoned  for  the  malet  and  sheet. 

"In  1875,  Mr.  A.  S.  Harris,  of  Port  Williams,  who  had  been 
fighting  canker-worms  for  two  years  with  poor  success,  got  a 
small  brass  hand-pump  with  single  and  double  orifice  nozzle 
from  Xew  York.  With  this  he  sprayed  his  trees,  using  Paris 
green,  1  teaspoonf  ul  to  10  quarts  of  water.  This  was  so  suc- 
cessful that  the  next  year  every  one  who  was  troubled  with 
the  canker-worm  provided  himself  with  a  pump  and  arsenites. 
Since  then  the  use  of  the  spray  has  been  continuous  where 
needed,  large,  powerful  pumps  fitted  to  casks  or  tanks  and 
placed  upon  wagons  being  used  for  the  purpose.  The  first  of 
these  was  gotten  up  by  myself  in  1880.  I  used  a  common  brass 
cylinder  lift  and  force  pump  fitted  with  suction  and  delivery 
hose.  With  this  I  tried  nearly  every  kind  of  nozzle  made ; 
some  are  good  and  some  are  worthless.  The  Vermorel  as  it 
is  now  made  is,  I  think,  the  best  for  all  purposes. 

"  During  the  past  four  years  spraying  has  assumed  a  much 
more  important  place  in  our  fruit  industry  than  formerly.  B}r 
using  the  Bordeaux  mixture  and  other  fungicides  with  Paris 
green,  and  spraying  early  and  frequently,  we  find  that  we  can 
keep  in  check  the  black  scab  on  the  apple  and  pear,  and  the 
black  knot  and  rot  of  the  plum,  as  well  as  destroy  the  insect 
pests  that  seem  to  have  been  increasing  proportionately  as  fast 
as  the  fruit  trees." 

Some  of  the  first  Canadian  publications  regarding  the  use  of 
fungicides  appeared  in  1888.1  Then  appeared  formulas  for 

*  Ann.  Hept.  Fruit  Growers'  Asfn,  1838,  105,  152. 
I 


114  The  Spraying  of  Plants. 

making  the  eau  celeste  and  the  original  Bordeaux  mixture  as 
first  prepared  in  this  country-  The  latter  was  given  by  Dr. 
Blley,  while  the  former  was  copied  from  one  of  the  United 
States  government  reports. 

In  the  annual  report  of  the  Canadian  Experimental  Farms 
for  1890,  there  is  an  account  of  experiments  made  by  Professor 
Craig  for  the  control  of  the  apple-scab  fungus.  The  copper 
compounds  were  here  used,  and  he  writes  me  that  "the  first 
work  done  in  Canada  on  this  line  was  in  1890,  under  my  direc- 
tion, at  Abbotsford,  Province  of  Quebec.  ...  It  is  safe  to  say 
that  the  Experimental  Farm  system  has  led  the  work  in  the 
practical  application  of  fungicides  in  Canada.  This  year 
[1894]  quite  a  large  proportion  of  our  most  progressive  fruit 
growers  are  using  Bordeaux  mixture  in  the  Hamilton  and 
Grimsby  districts  of  Ontario,  the  Island  of  Montreal,  the  east- 
ern townships  of  Quebec,  and  the  Annapolis  valley  of  Nova 
Scotia.  In  British  Columbia,  where  insects  are  more  injurious 
thus  far  than  fungous  diseases,  spraying  for  the  destruction  of 
those  foes  is  more  generally  practiced  than  for  the  prevention 
of  fungous  diseases." 

The  following  year  a  bulletin *  appeared  in  which  were  pub- 
lished methods  for  treating  the  apple-scab  fungus,  the  downy 
mildew  of  the  grape,  gooseberry  mildew,  and  there  were  also 
given  directions  for  making  the  carbonate  of  copper,  the  copper 
sulphate  solution,  the  ammoniacal  carbonate  of  copper,  and  the 
sulphide  of  potassium  solution.  This  bulletin  was  soon  fol- 
lowed by  another  2  report  from  the  same  author,  in  which  were 
mentioned  combinations  of  the  ammoniacal  copper  carbonate 
with  Paris  green,  and  the  copper  carbonate  in  suspension  and 
Paris  green. 

Early  in  1891  Fletcher  published  a  bulletin3  in  which  were 
mentioned  a  great  many  injurious  insects,  and  information  was 
given  regarding  the  preparation  and  use  of  various  insecticides. 
The  annual  report  of  the  stations  for  1891  also  contains  matter 
of  a  similar  nature,  and  thus  Canada  took  her  place  in  the  list 
of  those  countries  engaged  in  the  task  of  overcoming  the  in- 
numerable parasites  of  cultivated  plants. 

1  Craig,  Canada  Cent.  Exp.  Farm,  1891,  Bull.  10. 

2  Ann.  Kept.  Exp.  Farms,  1891,  144-148. 

a  Canada  Cent.  Exp.  Farm,  1891,  Bull.  2. 


CHAPTER  IV. 

THE  MATERIALS  AND   FORMULAS   USED  IN  SPRAYING. 

No  attempt  has  been  made  to  render  the  following  list  of 
materials  and  formulas  complete.  Such  a  record  would  require 
many  more  pages  than  can  here  be  devoted  to  the  subject,  and 
in  the  end  the  result  would  be  of  little  value,  since  the  majority 
of  the  substances  named  would  be  such  as  have  been  found  to 
possess  no  real  worth  and  have  in  consequence  been  discarded. 
But  many  of  the  materials  formerly  recommended  did  possess 
merit,  and  the  principal  reason  for  their  abandonment  has  been 
that  other  and  more  effective  substances  have  been  brought 
forward,  with  the  natural  result  that  the  first  was  displaced  by 
the  newcomer.  Such  formulas  are  frequently  interesting  as 
showing  the  steps  which  have  been  taken  in  the  development 
of  preparations  now  recognized  as  the  best,  and  they  may  also 
assist  in  doing  away  with  the  idea  that  a  fungicide  or  insecticide 
must  be  made  in  accordance  with  a  certain  definite  formula  in 
order  to  be  effective.  Nearly  all  the  following  directions  will 
bear  considerable  modification?  and  while  it  is  highly  desirable 
that  the  rules  be  followed  as  closely  as  possible,  since  they  have 
been  formulated  after  much  experience,  minor  changes  may  be 
made  with  comparative  safety,  and  good  results  will  still  follow. 
The  cost  of  the  more  important  substances  is  given  ;  the  first 
figure  refers  to  the  wholesale  price,  while  the  second  one  gen- 
erally refers  to  the  price  when  the  article  is  bought  at  retail. 

ACETO-ARSEXITE  OF  COPPER.       See  Paris  Green,  page  121. 

ALCOHOL.  —  A  30  per  cent  solution  of  alcohol  when  applied 
in  the  form  of  a  spray  is  useful  in  destroying  aphis  in  green- 
houses and  in  dwellings  where  the  use  of  other  methods  is  not 
advisable.  See  also  PYRETHRUM. 

115 


116  The  Spraying  of  Plants. 

ALUM  AND  PYKETHRUM. — 

Alum 2  ounces. 

Pyrethrum 3  large  tablespoonfuls. 

Water 10  gallons. 

First  dissolve  the  alum,  after  which  the  powder  may  be 
added.  This  mixture  has  been  recommended  as  possessing 
special  value  in  destroying  cabbage  worms.  The  applications 
are  made  by  means  of  a  watering-can  or  sprayer  when  the 
caterpillars  are  first  seen. 

AMMONIA  ;  AQUA  AMMONIA  ;  HARTSHORN  ;  VOLATILE  AL- 
KALI; NH3,  THE  GAS;  NHJIO,  DISSOLVED  IN  WATER. — 
Although  ammonia  alone  possesses  no  practical  value  as  an  in- 
secticide or  as  a  fungicide,  it  is  so  frequently  used  in  the  prepa- 
ration of  the  latter  that  it  has  interest  in  this  connection.  Am- 
monia is  the  term  popularly  used  to  denote  a  solution  of  the 
gas  in  water.  It  is  a  clear,  colorless  liquid,  lighter  than  water, 
and  possessing  an  overpowering,  pungent  odor.  It  has  a  strong 
alkaline  reaction,  and  is  a  solvent  of  probably  all  the  copper 
compounds  used  in  spraying.  It  is  for  this  reason  that  the 
article  is  of  such  importance  in  the  preparation  of  certain 
fungicides.  Commercial  ammonia  varies  greatly  in  strength, 
but  there  are  two  methods  of  indicating  its  degree  of  concen- 
tration. The  older  method  is  the  one  inaugurated  by  Beaume. 
He  used  an  instrument  called  a  hydrometer,  which  showed  the 
specific  gravity  of  liquids  in  accordance  to  an  arbitrary  scale 
invented  by  himself.  The  following  five  items  have  been 
selected  from  his  table  for  testing  liquids  lighter  than  water. 

In  the  first  column  are  degrees  taken  from  his  scale ;  the 
second  shows  the  specific  gravity  (G.)  of  the  liquid  as  compared 
with  water;  the  third  shows  the  per  cent  of  the  weight  of 
ammonia  gas  (%  Wt.)  as  found  in  the  liquids  which  register 
the  indicated  degrees  upon  the  scale.  The  figures  in  the  second 
and  third  columns  form  the  standards  of  measurement  now 
used  by  most  chemists : 

Beaume,  16°  indicates  .960  G.  or  *9.8  %  Wt. 
"        20°         "         .936  "    "  1(5.6      " 
«         22°         "         .924  "    "  20.4       " 
i<         24°         "          .913  "    "  24.         " 
"        20°        "         .901  "    "  28.6      " 


Materials  and  Formulas.  117 

The  26°  Beaume  ammonia  is  the  strong  ammonia  of  com- 
merce, and  in  the  end  it  is  the  cheapest  form  to  buy.  The 
liquid  loses  its  strength  very  rapidly  unless  it  is  kept  in 
tightly  closed  vessels,  bottles  having  glass  stoppers  being  among 
the  best.  It  must  be  handled  with  extreme  care,  for  the  fumes 
are  so  overpowering  that  serious  consequences  may  result  unless 
the  operator  has  at  all  times  fresh  air  to  breathe.  Strong 
ammonia  is  readily  diluted  with  water  to  any  desired  extent. 
Cost  of  22°  Beaume  seven  to  twenty  cents  per  pound. 

AMMOXIATED  COPPER  SULPHATE.  —  According  to  the  "  United 
States  Pharmacopoeia  "  of  1870,  this  substance  may  be  prepared 
as  follows  :  "  Take  of  sulphate  of  copper  half  a  Troy  ounce  ;  car- 
bonate of  ammonium  360  grains.  Rub  them  together  in  a  glass 
mortar  until  effervescence  ceases.  Then  wrap  the  ammoniated 
copper  in  bibulous  paper,  dry  it  with  a  gentle  heat,  and  keep  it 
in  a  well  stoppered  bottle."  The  sixteenth  edition  of  the  "  United 
States  Dispensary,"  1877,  contains  the  chemical  reactions  which 
take  place,  and  very  complete  information.  When  the  prepara- 
tion is  exposed  to  the  air  it  is  said  to  part  with  the  ammonia, 
resulting  in  the  formation  of  carbonate  of  copper  and  ammonium 
sulphate.  It  has  been  used  by  the  United  States  Department  of 
Agriculture  in  a  preparation  known  as  mixture  No.  5. 

ANALYSES  of  various  substances  are  here  inserted  together 
for  sake  of  convenience  of  comparison  (page  118).  The  table 
is  taken  from  the  Massachusetts  State  Agricultural  Experi- 
ment Station,  report  for  1893,  page  378. 

ARSENIC  ;  ARSENIOUS  ACID  ;  ARSENIOUS  ANHYDRIDE  ; 
WHITE  ARSENIC  ;  WHITE  OXIDE  OF  ARSENIC  ;  ARSENIC  TRI- 
OXIDE  ;  As2O3.  —  The  element  arsenic  stands  midway  between 
the  metals  and  the  non-metals.  When  pure  it  is  a  solid,  having 
a  metallic  lustre  and  a  steel-gray  color.  It  is  but  little  used, 
the  compound  commonly  sold  as  arsenic  being  arsenic  trioxide. 
This  is  a  white  crystalline  powder,  which  is  gritty  like  sand. 
It  is  soluble  in  cold  water  to  the  extent  of  1  part  in  100 ;  boiling 
water,  however,  dissolves  1  part  in  about  10  of  water. 

A  solution  of  white  arsenic  has  a  caustic  action  upon  foliage 
if  a  sufficient  amount  of  the  poison  is  present.  Danberry 
records1  an  experiment  in  which  one  hundred  square  feet  of 
young  barley  was  watered  with  a  solution  of  arsenious  acid, 

lJour.  Chem.  Soc.  of  London,  1862,  Vol.  xiv.  225. 


118  The  Spraying  of  Plants. 


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Materials  and  Formulas.  119 

made  by  dissolving  2  ounces  in  10  gallons  of  water.  After 
six  days  the  crop  looked  blighted,  but  the  plants  eventually 
recovered.  Most  plants  are  seriously  injured  when  not  more 
than  one-fourth  the  above  amount  is  used,  and  the  solution  for 
this  reason  requires  dilution  to  such  an  extent  that  its  value  as 
an  insecticide  is  largely  destroyed. 

Arsenious  acid  may  also  be  the  cause  of  the  death  of  a  plant 
if  applied  in  solution  at  the  roots.  Jager1  cites  many  cases  in 
which  different  plants  were  seriously  injured  or  killed  in  this 
manner,  the  action  of  the  poison  being  to  cause  the  entire  plant 
to  wilt  and  finally  to  die.  In  one  experiment,  some  young  oat 
plants  were  watered  with  a  solution  containing  1  part  of  arsenic 
in  480  of  water.  The  application  was  repeated  a  week  later, 
and  two  weeks  from  the  beginning  of  the  work  most  of  the 
plants  were  wilted  to  the  ground,  but  some  still  remained  fresh 
and  continued  to  grow.2  Cuttings  also  absorb  arsenic  with  the 
same  result  as  when  the  poison  enters  through  the  roots,  for  a 
chemical  examination  showed  arsenic  to  be  present  in  the 
tissues. 

In  view  of  the  above,  arsenious  acid  or  white  arsenic  cannot 
be  recommended  as  an  insecticide.  When  combined  with  other 
substances,  however,  it  can  be  used  with  safety.  Kilgore  pub- 
lished the  following  formula  for  combining  arsenic  and  lime  : 8 
"  A  very  cheap  insecticide,  having  the  same  insecticidal  proper- 
ties as  London  purple,  can  be  easily  made  by  boiling  together 
for  one-half  hour  in  2  to  5  gallons  of  water 

White  arsenic  (commercial) 1  pound, 

Lime  [unslaked] 2  pounds, 

and  dilute  to  required  volume,  say  100  gallons.  ...  It  is  desir- 
able that  the  lime  should  be  present  in  the  boiling  solution  of 
white  arsenic  since  it  renders  the  latter  insoluble  as  fast  as  it 
goes  into  solution,  thus  reducing  the  volume  of  water,  and 
shortening  the  time  for  obtaining  the  arsenite.  When  the 
white  arsenic  is  dissolved  alone,  a  larger  volume  of  water  and 
more  time  are  required.  When  lime  is  added  the  precipitation 

1  Dr.  Georg  v.  Jager,  "  Ueber  die  Wirkungen  des  Arseniks  auf  Pflanzen."    Stutt- 
gart, 1864. 
a  Ibid.  8,  9. 
»  N.  C.  Agric.  Exp.  Sla.  1891,  July,  Bull.  77  b,  7. 


120  The  Spraying  of  Plants. 

goes  on  slowly,  requiring  more  than  twenty-four  hours  to  reach 
completion."  This  precipitate  is  the  arsenite  of  lime,  which  is 
the  active  principle  of  London  purple: 

In  1875  McMurtrie,  then  the  chemist  at  the  Agricultural 
Department  in  Washington,  conducted  some  experiments  from 
which  he  drew  the  following  conclusion  :  "  Plants  have  not  the 
power  to  absorb  and  assimilate  from  the  soil  compounds  of 
arsenic,  and  that  though  arsenical  compounds  exert  an  in- 
jurious influence  upon  vegetation,  yet  this  is  without  effect 
until  the  quantity  present  reaches  for  Paris  green  about  900 
pounds  per  acre ;  for  arsenite  of  potassa  about  400  pounds  per 
acre;  f or arseniate  of  potassa  about  150  pounds  per  acre."1 

ARSENATE  OF  LEAD;  GYPSINE;  PB3(AsO4)2.  —  Arsenate  of 
lead  may  be  made  by  placing  "11  ounces  of  acetate  of  lead  and 
4  ounces  of  arsenate  of  soda  into  a  hogshead  containing  150 
gallons  of  water.  These  substances  quickly  dissolve  and  form 
arsenate  of  lead,  a  fine  white  powder  which  remains  in  suspen- 
sion in  water."  2  If  it  is  desired  to  make  any  variations  in  the 
above,  the  poison  can  be  prepared  by  using  29.93  per  cent  by 
weight  of  arsenate  of  soda,  and  70.07  of  acetate  of  lead.  These 
may  be  dissolved  separately,  and  when  united  the  arsenate  of 
lead  will  be  precipitated.  This  compound  is  much  lighter  than 
Paris  green  and  can  be  used  with  greater  freedom,  as  it  does 
not  injure  foliage.  The  conclusions  of  Fernald  in  regard  to 
the  amounts  to  use  are  that  "some  such  proportions  as  1,  1|, 
or  2  pounds  to  150  gallons  of  water  would  prove  entirely  satis- 
factory," 8  and  potato  beetles  were  killed  when  but  f  of  a  pound 
was  used.  At  the  Cornell  Station  this  poison  proved  unsatis- 
factory in  the  destruction  of  canker-worms 4  and  of  tent-cater- 
pillars in  1895. 

ARSENATE  OF  SODA;  NA2HAsO4.  —  This  material  has  also 
been  tried  by  Fernald,  but  it  injured  foliage  and  was  not  so 
effectual  in  destroying  insects  as  the  other  forms  commonly 
recommended.  Its  use  for  this  purpose  cannot  be  advised.5 

ARSENITE  OF  COPPER  ;   SCHEELE'S  GREEN  ;    CuHAsO3,  or 

1  Ann.  Kept.  IT.  S.  Com.  of  Agric.  1875,  147. 

2  Fernald,  Mass.  Hatch  Ag.ric.  Exp.  Sta.  1894,  April,  Bull.  24,  6. 
» Ibid.  5. 

*  Cornell  Agric.  Exp.  Sta.  1895,  Bull.  101. 

6  Mass.  Hatch  Agric.  Exp.  Sta.  1894,  April,  Bull.  24,  8,  9. 


Materials  and  Formulas.  121 

Cu3(AsO3)2.  —  "This  compound  is  to  be  had  by  adding  an 
aqueous  solution  of  arsenic  trioxide  to  an  ammonia-copper  sul- 
phate solution  ;  this  latter  solution  is  prepared  by  adding  am- 
monia to  a  solution  of  copper  sulphate  until  the  precipitate 
which  is  at  first  formed  dissolves."1  During  1895,  the  writer 
tested  this  arsenite,  and  the  results  showed  that  its  value  in 
destroying  the  codlin-moth  is  far  inferior  to  that  of  Paris 
green,  while  its  fungicidal  action  is  probably  greater  than  that 
of  any  other  compound  of  arsenic  and  copper.  The  United 
States  Department  of  Agriculture  conducted  a  similar  work 
during  the  year,  but  a  full  account  has  not  yet  been  published. 

Paris  Green;  Schweinfurth' s  Green;  Emerald  Green;  Mitis 
Green;  French  Green;  Ac eto-ar senile  of  Copper ;  (CuOAs2O3)3 — 
Cu(C2H3O9)2.  —  Paris  green  may  be  prepared  by  making  a  boil- 
ing solution  of  wrhite  arsenic  in  one  vessel,  and  a  similar  one 
of  acetate  of  copper  (verdigris)  in  another.  These  two  boiling 
solutions  are  then  combined,  and  Paris  green  is  precipitated. 
It  appears  as  a  more  or  less  fine  powder,  having  a  beautiful 
clear  green  color.  It  is  practically  insoluble  in  water,  but  dis- 
solves readily  in  ammonia.  It  is  for  this  reason  that  ammonia 
forms  such  an  excellent  test  for  determining  the  purity  of  the 
powder ;  all  sediment  which  the  ammonia  will  not  dissolve  may 
be  considered  as  foreign  matter. 

Ehrmann  has  given  the  composition  of  pure  Paris  green  to 
be  as  follows : a 

Copper  oxide 31.29 

Arsenious  acid 58.65 

Acetic  acid 10.06 

Most  samples,  even  of  the  purest  grades,  show  some  variations 
from  the  above. 

Since  very  nearly  all  the  arsenic  found  in  Paris  green  is  prac- 
tically insoluble  in  water,  it  is  true  that  this  poison  is  the  safest 
insecticide  now  in  general  use.  It  will,  nevertheless,  injure 
foliage,  sometimes  to  a  serious  extent,  if  several  applications 
are  made.  The  foliage  of  the  stone  fruits  is  particularly  sus- 
ceptible to  this  action,  although  even  the  apple  will  suffer.  The 

*  Shepard,  "  Elements  of  Chemistry."  1885,  245. 

2  Cited  by  Boss,  Ala.  Agric.  Exp.  Sta.  1894,  August,  Bull.  58,  5. 


122  The  Spraying  of  Plants. 

danger  may  be  avoided  by  adding  lime  to  the  liquid  in  which 
the  poison  is  held,  using  equal  parts  of  lime  and  arsenite,  as  is 
also  done  with  London  purple.  Paris  green  is  heavier  than  the 
latter,  and  must  be  more  frequently  stirred  when  in  water. 

Paris  green  possesses  some  value  as  a  fungicide.  This  is 
probably  due  to  the  presence  of  the  copper.  Although  the 
fungicidal  value  of  the  poison  is,  perhaps,  only  one-half  as  great 
as  that  of  the  Bordeaux  mixture,  its  protecting  influence  is 
fairly  strong,  as  has  been  shown  by  several  investigators.  It  is 
without  doubt  the  most  valuable  single  remedy  that  can  be 
used  in  an  orchard,  since  it  checks  most  insect  injuries,  and 
reduces,  to  a  marked  degree,  the  losses  occasioned  by  fungous 
diseases,  although  it  cannot  be  considered  as  a  very  energetic 
fungicide. 

Since  Paris  green  contains  less  soluble  arsenic,  it  can  be  used 
with  greater  freedom  than  London  purple,  as  there  is  less  danger 
of  injuring  the  foliage.  When  the  poison  first  came  into  use, 
more  of  it  was  applied  than  was  necessary  for  the  destruction  of 
the  insects.  The  amount  has  been  reduced  so  that,  at  present, 
the  following  may  be  accepted  as  a  safe  and  effective  mixture 
for  plants  when  only  one  or  two  applications  are  to  be  made. 
The  fine-grained  powder  is  to  be  preferred,  as  it  does  not  settle 
so  rapidly,  and  is  more  evenly  distributed  : 

Paris  green 1  pound. 

Water 150-300  gallons. 

The  more  concentrated  mixtures  should  be  used  only  upon 
plants  which  are  not  easily  injured,  as  the  eggplant  and  the 
potato;  in  other  cases,  when  the  insects  are  destroyed  with 
difficulty,  lime  should  be  added,  using  an  amount  equal  in  bulk 
to  that  of  the  poison.  It  is  always  safer  to  make  this  addition, 
even  when  the  mixture  is  more  dilute ;  the  amount  of  lime  used 
is  so  small  that  no  clogging  of  the  machinery  will  result,  and 
there  is  no  danger  of  injuring  the  plants. 

The  action  of  lime  in  overcoming  the  caustic  properties  of  the 
compounds  of  arsenic  has  suggested  the  use  of  the  Bordeaux 
mixture  in  combination  with  these  poisons,  but  especially  with 
London  purple  and  with  Paris  green.  These  mixtures  have 
now  been  in  use  for  several  years,  and  they  have,  almost  with- 
out exception,  given  excellent  results.  The  value  neither  of  the 


Materials  and  Formulas.  123 

insecticide  nor  of  the  fungicide  appears  to  be  weakened,  and 
the  presence  of  the  lime  in  the  Bordeaux  mixture  entirely  pre- 
vents any  injury  to  foliage.  The  arsenites  are  mixed  with 
the  fungicide  in  the  same  proportions  as  if  clear  water  were 
the  diluent.  Other  combinations  than  the  above  are  not  so 
satisfactory.1 

When  used  dry,  both  London  purple  and  Paris  green  may  be 
applied  pure,  provided  a  uniform  and  economical  application 
can*  be  made.  It  is,  however,  customary  to  mix  the  poisons 
with  flour,  leached  ashes,  plaster,  air-slaked  lime,  soot,  and 
similar  substances,  using  1  part  of  the  insecticide  to  from  5  to  50 
of  the  diluent,  the  required  amount  of  the  latter  being  less 
when  the  two  are  thoroughly  mixed  and  carefully  applied. 
But  since  the  introduction  of  improved  machinery,  the  liquid 
applications  are  generally  preferred.  The  price  of  Paris  green 
varies  from  eighteen  to  thirty  cents  per  pound. 

ARSENITE  OF  LIME  ;  CA3(AsO3)  2  (Normal).  —  An  arsenite  of 
lime  is  formed  when  arsenious  acid  and  lime  are  boiled  together, 
as  already  described  under  ARSENIC.  About  three-fourths  of 
London  purple  is  made  up  of  this  material,  according  to  analyses 
made  at  the  Cornell  experiment  station.2  The  arsenite  of 
lime  is  insoluble  in  water,  and  is  not  injurious  to  foliage.  As 
an  insecticide  it  is  probably  not  surpassed  by  any  compound  of 
arsenic;  it  is  advisable  to  mix  some  coloring  matter  with  the 
poison  to  lessen  the  danger  of  mistaking  it  for  some  other 
article. 

English  Purple  Poison.  —  An  analysis  of  this  preparation 
shows  the  total  amount  of  arsenic  trioxide  to  be  36.75  per  cent 
of  the  material.  Of  this  amount,  14.58  per  cent  is  soluble  in 
water.  This  insecticide  has  as  yet  been  tested  only  to  a  limited 
extent,  but  my  own  experience  with  it  has  been  that  the  fol- 
lowing proportions  may  be  used  with  success  against  the  potato 
beetle,  an  insect  which  is  destroyed  with  greater  difficulty  than 
many  other  pests : 

English  purple  poison 1  ounce. 

Lime 1      " 

Water 4  gallons. 

1  See  Cornell  Agric.  Exp.  Sta.  1891,  Dec.  Bull._35,  for  accounts  of  experiments 
in  combining  various  fungicides  and  insecticides. 

2  Cornell  Agric.  Exp.  Sla.  1890,  July,  Bull.  18, 36. 


124  The  Spraying  of  Plants. 

Considerable  difficulty  has  been  experienced  in  mixing  the 
poison  with  water.  Much  of  it  floats  upon  the  surface  in  the 
form  of  bubbles,  and  it  is  almost  impossible  to  wet  all  the  poi- 
son. When  once  thoroughly  wet,  it  remains  in  suspension 
fairly  well.  The  color  of  the  mixture  is  darker  than  that  of 
London  purple. 

London  Purple. — The  chemical  composition  of  London  pur- 
ple is  variable.  Two  analyses  published  by  Bailey l  are  as  fol- 
lows :  "1.  Arsenic,  43.65  per  cent;  rose  aniline,  12.46;  lime, 
21.82;  insoluble  residue,  14.57;  iron  oxide,  1.16;  and  water, 
2.27.  2.  Arsenic,  55.35  per  cent;  lime,  26.23;  sulphuric  acid, 
.22 ;  carbonic  acid,  .27 ;  moisture,  5.29."  Some  samples  show 
that  fully  one-half  of  the  arsenic  is  in  a  soluble  condition,  and 
this  easily  explains  the  scorching  of  the  foliage  to  which  Lon- 
don purple  has  been  applied.  In  the  manufacture  of  certain 
dyes  this  substance  appears  as  a  waste  product,  which  accounts 
for  the  above  variations.  The  finely  divided  condition  of  the 
powder  is  one  strong  point  in  its  favor.  It  remains  sus- 
pended in  water  a  long  time,  and  the  liquids  with  which  it  is 
mixed  require  comparatively  little  agitation.  The  value  of  Lon- 
don purple  does  not  rest  in  its  coloring  matter,  for  this  can  be 
removed  and  the  arsenite  still  be  as  effective  as  before.  In 
order  to  check  the  caustic  action  of  the  poison,  it  is  well  to  add 
an  amount  of  lime  fully  equaling  in  weight  that  of  the  drug ; 
the  dissolved  arsenic  will  then  be  converted  into  an  insoluble 
arsenite  of  lime. 

The  following  formula  indicates  the  manner  of  its  use : 

London  purple 1  pound. 

Lime 1      " 

Water 200-300  gallons. 

When  less  water  is  used,  the  amounts  of  the  other  ingredi- 
ents should  be  reduced  in  proportion.  In  making  applications, 
the  liquid  should  be  stirred  sufficiently  to  prevent  the  solid  par- 
ticles from  settling  to  the  bottom. 

If  London  purple  is  used  without  lime,  foliage  is  commonly 
scorched  when  1  pound  in  200  gallons  of  water  is  used,  but  more 
dilute  mixtures  will  prove  more  satisfactory.  This  arsenite 
should  cost  from  six  to  fifteen  cents  per  pound. 

i  Horticulturist's  Rule-Book,  third  edition,  2. 


Materials  and  Formulas.  125 

Paris  Purple.  —  This  substance  closely  resembles  English 
purple  poison,  being  of  a  very  deep  maroon  color.  Chemical 
analysis  shows  34.1  per  cent  of  arsenic  trioxide,  40.7  per  cent  of 
this  amount  being  soluble  in  water.  It  may  be  used  in  the 
same  manner  as  recommended  for  English  purple  poison,  and 
it  is  also  defective  from  the  fact  that  it  does  not  mix  readily 
with  water. 

BENZINE.  —  Benzine  has  been  used  in  the  place  of  the 
bisulphide  of  carbon  for  the  destruction  of  insects  infesting 
seeds.  It  is  not  so  energetic  as  the  latter,  so  that  larger  quan- 
tities of  the  liquid  must  be  used. 

BISULPHIDE  OF  CARBON.     See  CARBON  BISULPHIDE. 

BLIGHT  POWDER.     See  SULPHATED  SULPHUR. 

BLUE  STONE.     See  COPPER  SULPHATE. 

BLUE  VITRIOL.     See  COPPER  SULPHATE. 

BORAX.  —  Borax,  whether  used  as  a  powder  or  in  a  strong 
solution,  is  of  value  in  driving  roaches  and  similar  vermin  from 
the  places  they  frequent.  ^ 

BORDEAUX  MIXTURE;  COPPER  MIXTURE  OF  GIRONDE; 
COPPER  SULPHATE  AND  LIME  MIXTURE;  MILLARDET  MIX- 
TURE. —  The  early  history  of  this  fungicide  has  already  been 
thoroughly  discussed,  as  well  as  the  first  formulas  adopted  for 
its  manufacture.  The  chemical  composition  of  the  mixture  is 
by  no  means  clear,  for  although  at  first  thought  it  would 
seem  that  the  reactions  which  take  place  when  the  copper 
sulphate  solution  and  the  milk  of  lime  are  brought  in  con- 
tact with  each  other  must  be  quite  simple,  still  such  is  not  the 
case.  The  new  compounds  formed  vary  with  the  proportion  of 
the  ingredients,  and  all  who  have  observed  the  behavior  of  the 
mixture  must  have  noticed  that  it  varies  in  color  with  the  dif- 
ferent amounts  of  lime  added,  sometimes  being  intensely  blue, 
again,  much  paler  blue ;  and  frequently  a  greenish  tinge  will  be 
noticed,  this  being  most  marked  when  a  small  amount  of  lime 
is  present.  Since  the  chemistry  of  the  mixture  has  not  yet 
been  accurately  determined,  it  will  be  of  little  avail  to  discuss 
the  various  theories  regarding  its  composition,  and  only  those 
concerning  which  there  is  the  most  certainty  may  here  be  briefly 
mentioned. 

When  the  mixture  was  first  studied,  it  was  supposed  that  the 
union  of  the  two  ingredients  caused  the  formation  of  copper 


126  The  Spraying  of  Plants. 

hydrate,  water,  and  the  sulphate  of  lime,  in  accordance  with 
the  following  reaction  : 

CuS04,  5H20      +     CaOH20    =  Cu(OH)2  +  CaSO4 -f  <5H2O. 

copper  sulphate  crystals  +water-slaked  lime=copper  hydrate+lime  sulphate-fwater. 

It  was  soon  found,  however,  that  these  changes  would  not 
account  for  the  various  phenomena  noticed  during  its  manufac- 
ture. Careful  observation  has  shown  that  when  lime  is  added 
to  a  certain  point,  the  mixture  assumes  a  greenish  tinge,  due 
to  the  formation  of  precipitates,  probably  basic  sulphates  of 
copper,  in  which  this  color  predominates.  It  is  a  popular  idea 
that  the  addition  of  lime  is  necessary  in  order  to  neutralize  any 
free  sulphuric  acid  which  may  be  present.  If  such  were  the  case, 
the  precipitate  would  be  largely  a  sulphate  of  lime,  with  no  hy- 
droxide of  copper.  When  lime  is  added  to  a  solution  of  copper 
sulphate,  the  latter  compound  is  entirely  broken  up  and  new  ones 
formed.  The  presence  of  the  basic  sulphate  of  copper  is  thus 
explained.  When  sufficient  lime  is  added  so  that  the  copper 
sulphate  is  entirely  neutralized,  most  of  the  copper  is  probably 
precipitated  in  the  form  of  a  hydrate.  But  at  least  one  other 
compound  is  sometimes  formed  in  the  Bordeaux  mixture.  This 
appears  most  commonly  when  an  excess  of  lime  has  been  added 
to  a  concentrated  form  of  the  mixture.  It  ma}7  be  a  double 
basic  sulphate  of  copper  and  lime,  but  so  little  work  has  been 
done  regarding  its  formation  and  action  that  no  definite  state- 
ments can  be  made. 

Whatever  may  be  the  composition  of  the  Bordeaux  mixture, 
it  is  certain  that  all  but  a  trace  of  the  copper  is  in  the  form  of 
a  precipitate  or  sediment  which  is  practically  insoluble  in  water. 
This  settles  to  the  bottom,  leaving  a  clear  solution  above.  This 
solution  is  of  no  value  as  a  fungicide,  for  the  sediment  contains 
all  the  compounds  useful  for  this  purpose,  and  therefore  the 
mixture  should  be  kept  thoroughly  stirred  that  the  sediment 
may  be  uniformly  applied. 

But  the  reactions  which  take  place  in  the  Bordeaux  mixture 
do  not  cease  when  the  material  is  applied  to  the  plant.  It  is 
well  known  that  carbonic  acid  will  cause  considerable  quanti- 
ties of  copper  to  enter  into  solution  again  if  the  acid  comes  in 
contact  with  the  copper  sediment  of  the  mixture.  The  chemi- 


Materials  and  Formulas.  127 

cal  changes  which  take  place  have  not  been  fully  determined, 
but  Professor  J.  T.  Willard  has  suggested  the  following:1 

2  (Cu(OH)2,  CuSO4)  +  CO2  = 

basic  copper  sulphate  carbonic 

acid  gas 

2  CuSO4  -f  Cu(OH)2  +  CuCO3  +  H2O. 

copper  copper  copper  water, 

sulphate  hydrate  carbonate 

This  theory  appears  to  be  very  plausible  and  several  facts 
tend  to  support  it.  When  dew  or  rain-water  gathers  upon  a 
leaf,  the  liquid  always  contains  a  certain  amount  of  carbonic 
acid  gas  in  solution,  obtaining  it  both  from  the  air  and  from  the 
leaf  itself.  If  the  foliage  has  been  sprayed  with  the  Bordeaux 
mixture,  the  carbonic  acid  comes  in  contact  with  the  copper 
sediment,  and  a  certain  amount  of  the  copper  is  dissolved. 
This  much  has  been  proved.  That  the  dissolved  copper  may 
be  in  the  form  of  the  sulphate  is  also  very  probable,  since  it  is 
well  known  that  a  solution  of  copper  sulphate  is  injurious  to 
foliage,  and  well-prepared  Bordeaux  mixture  has  also  caused  a 
similar  injury.  This  alone  is  not  very  convincing,  but  when  it  is 
considered  that  the  injury  following  the  use  of  the  fungicide  does 
not  take  place  immediately  as  a  rule,  but  only  after  the  sedi- 
ment has  been  exposed  to  the  air  for  some  time,  the  position  is 
strengthened.  If,  however,  the  weather  is  of  such  a  nature  that 
the  foliage  is  constantly  wet  by  light  showers,  not  enough  rain 
falling  to  wash  off  the  leaves  but  only  to  wet  them,  and  if  this 
were  continued  for  some  time,  much  injury  might  be  expected 
to  result  from  the  use  of  even  such  a  safe  preparation  as  the 
Bordeaux  mixture.  During  the  early  part  of  the  year  1894 
such  conditions  did  exist,  and  much  complaint  was  heard 
regarding  the  injury  done  to  both  apples  and  pears  by  the 
use  of  this  remedy.  It  seems  very  probable  that  the  carbonic 
acid  should  unite  with  some  of  the  copper,  and  also  with  some 
of  the  lime,  although  no  mention  is  made  of  this  in  the  above 
reaction,  and  that  pure  copper  sulphate  should  result.  As  the 
amount  of  this  compound  gradually  increases,  the  injury  to 
the  foliage  and  the  fruit  naturally  follows. 

i  Cited  by  Fairchild,  U.  S.  Dept.  of  Agric.  J>iv.  Veg.  Path.  Bull.  6,  14. 


128  The  Spraying  of  Plants. 

The  formation  of  the  carbonate  of  lime  may  take  place  as 
soon  as,  or  even  before,  the  appearance  of  the  copper  sulphate, 
since  the  acid  would  probably  act  more  energetically  upon  the 
hydrate  of  lime  than  upon  the  copper  compounds ;  therefore 
the  appearance  of  the  copper  sulphate  would  depend  to  a 
certain  extent  upon  the  absence  of  the  hydrate  of  lime.  This 
well  explains  the  tardiness  with  which  the  Bordeaux  mixture 
injures  foliage.1 

Several  corollaries  follow  from  the  above,  and  these  have 
considerable  practical  bearing  on  the  method  of  making  the 
mixture. 

If  a  larger  amount  of  lime  is  used  than  is  required  to  satisfy 
the  immediate  chemical  changes  which  take  place,  the  more 
slowly  will  the  fungicidal  action  of  the  Bordeaux  mixture  ap- 
pear. In  wet  seasons  this  is  an  advantage,  since  the  mixture 
will  retain  its  efficiency  longer,  and  less  injury  will  be  done. 
The  disadvantages  of  using  much  lime  are  very  easily  realized 
by  all  who  have  applied  the  mixture.  The  machinery  is  apt 
to  be  clogged,  and  the  liquid  becomes  more  difficult  to  handle 
and  to  apply  uniformly.  The  particles  of  lime  probably  also 
offer  more  resisting  surface  to  rain  in  heavy  showers,  and  more 
of  the  material  will  be  washed  from  the  trees.  The  use  of  as 
small  an  amount  of  lime  as  possible  would  therefore  appear  to 
be  desirable,  but  such  is  the  case  only  to  a  limited  extent. 

The  use  of  the  ferrocyanide  of  potassium  test,  or  Patrigeon's 
method,  has  already  been  mentioned  on  page  46.  This  test 
shows  exactly  how  much  lime  is  necessary  to  satisfy  all  imme- 
diate chemical  changes,  and  it  serves,  therefore,  as  an  index  of 
the  minimum  amount  required.  The  Bordeaux  mixture  so 
prepared  is  of  an  intense  blue,  and,  as  more  commonly  made, 
the  amount  of  sediment  is  comparatively  small.  When  applied 
to  plants  it  is  easily  handled,  and  is  in  this  respect  the  most 
satisfactory  preparation.  Its  fungicidal  action  probably  begins 
as  soon  as  the  application  is  made,  and  the  copper  is  more  ener- 
getic than  when  it  is  in  the  presence  of  considerable  quantities  of 

1  For  more  detailed  accounts  of  the  chemistry  of  Bordeaux  mixture  consult  the 
work  of  Chester  and  of  Sostegni.  An  abstract  of  Sostegni's  article  is  in  Cornell 
Agric.  Exp.  Sla.  1892,  Bull.  48.  Fairchild  has  written  an  exhaustive  article  on 
this  fungicide,  which  was  published  as  Bull.  6  of  the  Division  of  Vegetable  Pathol- 
ogy, U.  S.  Department  of  Agriculture,  and  entitled  "  Bordeaux  Mixture  as  a  Fungi- 
cide." 


Materials  and  Formulas.  129 

lime.  The  adhesive  properties  are  perhaps  greater  than  those 
of  any  of  the  other  mixtures  of  this  nature,  and  there  are  thus 
several  features  which  recommend  the  method  for  general  use. 
But  the  season  of  1894  showed  that  the  preparation  is  not  a  very 
safe  one  to  use  except  in  dry  seasons,  or  in  regions  where  the 
rainfall  and  dew  are  but  slight.  In  the  presence  of  much  water, 
the  mixture  will  injure  both  foliage  and  fruit,  whatever  may  be 
the  compound  doing  the  mischief,  and  for  this  reason  when  so 
prepared  it  cannot  be  unqualifiedly  recommended.  In  some  sea- 
sons it  may  be  used  with  impunity,  while  in  others  it  may  cause 
a  loss  which  will  more  than  overbalance  any  advantage  derived. 
The  ferrocyanide  of  potassium  test,  is  of  great  value  in  deter- 
mining how  much  lime  is  actually  required,  and  in  this  manner 
it  may  serve  as  a  check  when  the  ingredients  are  not  weighed, 
and  then  this  neutral  condition  may  be  taken  as  a  starting-point 
for  the  addition  of  more  lime. 

In  making  the  Bordeaux  mixture  by  the  aid  of  the  ferrocya- 
nide of  potassium  test,  certain  points  must  be  borne  in  mind  in 
dissolving  the  copper  sulphate.  (See,  also,  COPPER  SULPHATE.) 
A  definite  proportion  should  exist  between  the  amount  of  the 
salt  used  and  the  water  in  wrhich  it  is  dissolved.  This  is 
necessary  so  that  the  amount  of  the  copper  compound  in  a 
given  amount  of  water  may  be  known.  The  more  common 
method  is  to  dissolve  either  1  or  2  pounds  of  copper  sulphate 
in  1  gallon  of  water.  Any  desired  amount  can  then  easily  be 
obtained  by  first  stirring  the  stock  solution  thoroughly,  and 
then  taking  out  the  quantity  which  holds  the  desired  amount. 
The  milk  of  lime  is  then  added  to  the  diluted  solution  until  a 
few  drops  of  the  dissolved  ferrocyanide  of  potassium  (which 
see)  give  no  brown  discoloration  when  added  to  the  mixture. 
A  better  way  of  using  the  test,  however,  is  to  add  some  of  the 
mixture  to  a  few  drops  of  the  solution,  the  latter  being  held  in 
a  butter  dish  or  other  article  of  white  porcelain.  This  will 
show  the  presence  of  the  red  precipitate  when  it  cannot  be 
detected  by  the  old  method  of  adding  the  test  solution  to  the 
mixture.  It  is  probable  that  much  of  the  injury  which  fol- 
lowed the  use  of  the  Bordeaux  mixture  in  1894  was  caused  by 
an  insufficient  amount  of  lime  having  been  used,  this  being  due 
to  the  fact  that  the  ferrocyanide  of  potassium  test  did  not  show 
plainly  the  true  condition  of  the  preparation.  A  person  ex- 


130  The  Spraying  of  Plants. 

perienced  in  making  the  mixture  can  tell  by  its  color  when 
sufficient  lime  has  been  added,  but  he  cannot  always  tell  how 
much  to  add  in  excess  of  the  amount  demanded  by  the  test. 
For  this  reason  it  is  safer  to  use  a  definite  formula,  provided 
the  materials  are  fairly  pure,  since  then  there  is  less  chance  of 
a  mistake ;  this  applies  especially  to  beginners. 

Another  test  sometimes  employed  is  to  insert  into  the  mix- 
ture a  polished  iron  surface.  If  an  insufficient  amount  of  lime 
is  present,  so  that  some  copper  still  remains  in  solution,  the  iron 
will  become  coated  with  this  metal.  The  test  is  said  to  be  very 
delicate. 

It  is  probably  true  that,  as  a  rule,  each  extreme  should  be 
avoided.  The  formulas  at  present  in  use  in  America  may  be 
divided  into  two  classes,^- those  in  which  the  ingredients  are 
weighed,  and  those  in  which  the  ferrocyanide  of  potassium  test 
is  used.  Among  the  former  we  have  the  following : 

The  "  Standard,"  or  3.6  per  cent  Bordeaux  Mixture. 

Copper  sulphate 6  pounds. 

Quicklime 4       " 

Water 22  gallons. 

This  formula  was  at  first  extensively  used,  but  it  was  found 
that  a  more  dilute  mixture  would  answer  the  purpose  equally 
well,  so  it  has  been  abandoned  for  the  mixture  which  may  now 
be  termed 

The  " Normal"  or  1.6 per  cent  Bordeaux  Mixture. 

Copper  sulphate 6  pounds. 

Quicklime 4       " 

Water 45  gallons. 

This  formula,  or  one  in  which  the  amount  of  water  varies 
from  40  to  50  gallons,  may  now  be  considered  the  most  popular 
in  America.  Sixty  gallons  of  water  should  be  used  when 
spraying  peaches.  If  air-slaked  lime  is  used  in  place  of  the 
fresh  article,  the  amount  should  be  doubled,  and  even  then  its 
use  cannot  be  recommended,  since  too  little  is  yet  known  re- 
garding the  composition  and  action  of  the  mixture  prepared 
in  this  manner.  By  a  3.6  per  cent  Bordeaux  mixture  is  meant 
one  in  which  the  weight  of  the  copper  sulphate  is  equal  to  3.6 
per  cent  of  the  weight  of  the  water,  considering  1  gallon  to 


Materials  and  Formulas.  131 

weigh  8.345  pounds.  For  the  same  reason  the  normal  mixture 
may  be  termed  a  1.6  per  cent  Bordeaux,  as  the  6  pounds  form  such 
a  percentage  of  the  weight  of  the  water.  This  method  of  desig- 
nating the  various  mixtures  is  the  one  generally  adopted  in 
Europe,  and  it  is  convenient  here  for  purposes  of  comparison. 

Occasionally  the  recommendation  is  made  to  add  1  quart  of 
molasses  to  the  above  mixture  in  order  to  increase  its  adhesive 
properties.  As  a  matter  of  fact,  the  addition  is  rarely  made, 
and  is  scarcely  necessary,  since  the  mixture,  even  when  used 
alone,  is  one  of  the  most  adhesive  of  fungicides.  The  addition 
of  from  1  to  2  pounds  of  soap  has  been  made  for  the  same 
purpose,  and  also  to  make  the  mixture  spread  more  evenly. 
The  value  of  the  mixture  is  slightly  increased  by  such  additions ; 
nevertheless,  they  are  scarcely  necessary. 

In  Italy  the  milk  of  lime  is  not  used  in  making  the  Bordeaux 
mixture,  but  in  its  place  lime  water,  which  is  a  saturated  solu- 
tion, is  added  to  the  copper  sulphate  solution.  This  makes  a 
very  dilute  mixture,  as  the  following  formula  of  Cavazza  shows. 

Cavazza's  Bordeaux  mixture  (Italian)  : 

Copper  sulphate 720  grams. 

Lime  water 100  liters. 

This  is  a  neutral  mixture  which  contains  about  .072  per  cent 
of  copper  sulphate.  It  is  very  highly  recommended  in  Italy, 
and  Professor  Cavazza  writes  me  that  he  has  used  the  mixture 
so  prepared,  since  1886,  for  controlling  fungous  diseases  of  the 
grape  as  well  as  those  of  the  peach,  and  in  general  it  is  there 
used  in  preference  to  other  formulas.  The  French,  however, 
use  a  mixture  having  from  1  to  2  per  cent  of  copper  sulphate, 
the  milk  of  lime  being  preferred  to  a  saturated  solution. 

When  the  Bordeaux  mixture  is  made  according  to  a  certain 
formula,  a  few  points  must  be  observed  which  it  is  unnecessary 
to  notice  when  the  ferrocyanide  of  potassium  test  is  used.  The 
directions  given  above  call  for  1  to  2  pounds  of  copper  sulphate 
to  each  gallon  of  water,  the  smaller  amount  being  preferable. 
This  solution  should  be  diluted  one-half  before  the  lime  is  added. 
If  too  little  water  is  present  when  the  two  ingredients  are  brought 
together,  the  mixture  thickens  up  like  sour  milk,  and  it  must 
be  thoroughly  stirred  to  change  it  to  a  more  liquid  form.  Such 
concentrated  mixtures  are  not,  on  the  whole,  the  best  to  make, 


132  The  Spraying  of  Plants. 

as  in  my  experience  the  sediment  is  more  coarse  than  when  a 
larger  amount  of  water  allows  of  a  more  free  intermingling  of 
the  two  ingredients.  Two  gallons  of  water  to  every  pound  of 
copper  sulphate  is  a  safe  proportion,  and  the  use  of  still  more 
water  might  be  of  benefit.  All  immediate  chemical  action  has 
largely  ceased  a  few  minutes  after  the  lime  and  the  copper 
sulphate  have  been  brought  together,  and  the  mixture  may 
then  be  diluted  as  desired,  and  immediately  applied. 

The  most  convenient  method  of  making  the  mixture  is  to 
have  a  stock  solution  of  definite  strength,  so  that  any  desired 
amount  of  the  sulphate  may  be  taken.  This  should  be  diluted 
as  already  described,  and  then  the  milk  of  lime  should  be  added. 
This  ingredient  may  also  be  prepared  in  large  quantities  before 
using;  it  will  keep  indefinitely  if  kept  covered  with  water. 

The  sediment  in  the  Bordeaux  mixture  remains  in  suspen- 
sion much  better  during  the  first  twenty-four  hours  after 
the  two  ingredients  are  brought  together;  in  fact,  it  settles 
so  slowly  that  an  agitator  is  scarcely  necessary  during  this 
period.  But  after  a  day  or  two,  probably  on  account  of  some 
physical  change  in  the  mixture,  the  sediment  rapidly  settles, 
rendering  the  use  of  an  agitator  essential  for  a  uniform  appli- 
cation. To  what  extent  this  change  affects  the  fungicidal 
value  of  the  mixture  is  not  known,  but  if  care  is  exercised  in 
keeping  the  old  mixture  well  stirred,  it  is  probable  that  good 
results  will  follow.  Such,  at  least,  has  been  the  writer's  experi- 
ence with  Bordeaux  mixture  which  was  allowed  to  stand  several 
weeks  before  it  was  applied  to  the  apple  trees  which  were  being 
treated. 

If  the  Bordeaux  mixture  has  been  imperfectly  made,  or  if  it 
is  not  applied  with  proper  machinery,  it  will  be  found  better  to 
strain  either  the  lime  before  it  is  added  to  the  copper  sulphate 
solution,  or  else  the  mixture  before  it  is  applied,  the  former 
being  perhaps  the  better  plan.  The  mixture  should  be  kept 
constantly  stirred  when  the  application  is  made. 

The  dried  sediment  has  been  used  in  place  of  the  liquid  form, 
but  the  results  were  not  equally  satisfactory.  It  was  found 
that  about  four  times  as  much  material  was  necessary  when  the 
powder  was  applied,  and,  besides,  its  efficiency  was  apparently 
less  marked.  (See,  also,  DAVID'S  POWDER.) 

Bordeaux  mixture  is  said  to  possess  a  certain  value  as  an 


Materials  and  Formulas.  133 

insecticide,  but  this  action  is  not  sufficiently  great  that  its  use 
for  this  purpose  can  be  recommended.  Flea  beetles  appear  to 
be  most  easily  overcome  or  driven  away  by  this  preparation, 
and  it  is  possible  that  it  can  be  used  to  advantage  for  this  pur- 
pose when  the  pest  causes  much  damage.1  Uniformly  good 
results  have  not  always  followed  its  use  for  this  purpose,  how- 
ever. 

BORDEAUX  MIXTURE  AND  MOLASSES.  —  Ferret  mentions  the 
following  formula  as  possessing  especial  merit : 2 

Copper  sulphate 4?  pounds. 

Quicklime 4*       " 

Molasses 4*      " 

Water 30  gallons. 

Dissolve  the  lime  in  24  gallons  of  water.  To  this  add  the 
molasses,  which  has  been  diluted  with  3  gallons  of  water ;  stir 
this  well  and  pour  in  the  copper  sulphate,  also  dissolved  in  3 
gallons  of  water.  The  precipitate  settles  slowly,  leaving  a 
greenish  colored  liquid  above.  This  color  is  a  proof  of  the  suc- 
cess of  the  operation.  The  mixture,  even  wThen  diluted  to  40  or 
50  gallons,  may  be  recommended  for  trial,  although  in  this 
country  it  will  scarcely  prove  superior  to  the  preparation  com- 
monly employed.  Sugar  has  also  been  used  in  place  of  the 
molasses. 

BORDEAUX  MIXTURE,  DRIED.     See  DAVID'S  POWDER. 

BUHACH.     See  PYRETHRUM. 

CARBOLIC  ACID;  PHENIC  ACID;  PHENOL;  C6H6O.  —  Car- 
bolic acid  is  a  powerful  poison  to  the  lower  forms  of  life,  and 
is  very  extensively  used  as  an  antiseptic.  Its  value  as  an  in- 
secticide or  as  a  fungicide  is,  however,  comparatively  slight, 
and  it  cannot  be  recommended  for  such  use.  It  has  been  very 
thoroughly  tested  however,  and  the  following  has  been  fre- 
quently recommended  for  the  destruction  of  root  insects : 

Carbolic  acid 1  part. 

Water 50-100  parts. 

1  For  further  details  regarding  this  subject  the  reader  is  referred  to  Jones,  Vt. 
Agric.  Exp.  Sta.  1S94,  Bull.  44,  95 ;  Halsted,  N.J.  Agric.  Exp.  Sta.  1895,  Bull. 
107, 13  ;  Lodeman,  Cornell  Agric.  Exp.  Sta.  1895,  Bull.  86,  58.  Ann.  Sept.  Vt. 
Agric.  Exp.  Sta.  1894,  12,  95  et  seq. 

*  Jour.  d'Ag.  Prat.  1892,  April,  508. 


134  The  Spraying  of  Plants. 

CARBOLIC  ACID  AND  GLYCERINE  : 

Carbolic  acid \  pint. 

Glycerine 1  pound. 

Soap-suds 10  gallons. 

An  emulsion  should  be  made  of  these  ingredients.  Apply 
against  sucking  insects. 

CARBOLIC  ACID  AND  SOAP. —  An  emulsion  of  carbolic  acid 
and  a  soap  solution  may  be  made  very  readily  according  to  the 
following  formula,  and  the  product  possesses  considerable  in- 
secticidal  value,  largely  on  account  of  the  presence  of  the  soap : 

Carbolic  acid 1  pint. 

Soft  soap  (hard  soap  4  pound) 1  quart. 

Hot  water 2  gallons. 

The  soap  is  first  dissolved  in  the  water,  after  which  the  acid 
is  added ;  an  emulsion  is  then  produced  by  thorough  agitation. 
It  destroys  insects  by  coining  in  contact  with  them,  and  may  be 
applied  as  a  wash  or  in  the  form  of  a  spray.  It  should  be  used 
upon  dormant  wood  only. 

CARBOLIC  ACID  EMULSION.  —  The  stock  solution  is  pre- 
pared as  in  the  preceding,  but  should  be  diluted  with  thirty 
parts  of  water  before  being  applied  to  foliage. 

CARBOLIZED  PLASTER.  —  Carbolic  acid  is  occasionally  mixed 
with  some  dry  powder  as  plaster,  air-slaked  lime,  road  dust, 
etc.,  and  the  two  are  then  applied  together.  It  possesses  little 
value,  but  the  recommendation  is  to  use  : 

Carbolic  acid 1  pint. 

Plaster  or  other  powder 50  pounds. 

It  is  most  useful  when  applied  to  plums  which  suffer  from 
the  curculio.  If  it  is  used  with  lime,  it  is  effective  in  destroy- 
ing slugs  upon  all  plants. 

CARBONATE  OF  COPPER.  See  COPPER  CARBONATE. 

CARBON  BISULPHIDE  ;  BISULPHIDE  OF  CARBON;  FUMA;  CS2. 
—  This  is  a  clear,  colorless  liquid,  highly  volatile  and  inflamma- 
ble. The  commercial  article  has  a  powerful  and  disagreeable 
odor.  The  fumes  are  poisonous  to  animal  life,  and  in  this  lies 
the  value  of  the  liquid.  Its  insecticidal  properties  seem  to  have 


Materials  and  Formulas.  135 

been  first  utilized  by  Louis  Dayere,  formerly  professor  of  agri- 
culture at  the  Institute  of  Versailles.  He  used  the  liquid  in 
Algiers  for  preventing  insects  from  injuring  stored  wheat,  and 
it  is  now  commonly  used  in  this  country  for  similar  purposes.1 
The  vapor  is  heavy  and  it  is  better,  when  possible,  to  apply 
the  liquid  above  the  parts  to  be  treated,  so  that  the  entire  space 
may  be  more  quickly  filled.  The  amount  of  liquid  to  use  will 
vary  with  the  tightness  of  the  receptacle,  and  the  character  of 
the  product  to  be  protected.  For  growing  plants  it  is  not  advis- 
able to  evaporate  more  than  20  or  25  minims  in  a  vessel  con- 
taining from  2  to  3  cubic  feet  of  space,  this  being  an  equivalent 
of  1  pint  of  the  liquid  to  about  1000  cubic  feet  of  space,  or  to  1 
ton  of  grain.  If  so  used,  the  receptacle  should  be  as  nearly  air- 
tight as  possible.  When  grain  or  other  seeds  are  treated,  the 
amount  can  be  advantageously  increased,  and  much  larger  quan- 
tities than  the  above  can  be  used  without  fear  of  injury.  All 
vermin  that  live  underground  can  also  be  successfully  extermi- 
nated. Ants'  nests  may  be  destroyed  by  making  a  hole  in  the 
center  of  the  nests,  and  then  pouring  in  2  or  3  teaspoonfuls  of 
the  liquid,  after  which  the  hole  should  be  tightly  closed  with 
earth.  VToodchucks  and  gophers  can  easily  be  killed  by  means 
of  this  poison ;  about  a  gill  of  the  fluid  is  poured  upon  rags  or 
cotton,  and  these  are  then  forced  into  the  animal's  burrow. 
The  opening  should  then  be  closed,  and  the  woodchuck  will 
cause  no  more  trouble  if  all  the  holes  are  similarly  treated. 

Subterranean  applications  for  the  destruction  of  insects  have 
also  been  successfully  made.  The  phylloxera  of  the  grape  has 
been  so  destroyed,  and  the  cabbage  root-maggot  may  be  over- 
come in  this  manner  more  advantageously  than  in  any  other. 
A  machine  known  as  the  McGowen  bisulphide  of  carbon  in- 
jector2 was  invented  in  1894  for  the  purpose  of  making  such 
applications,  so  the  liquid  may  now  be  used  quickly  and  effec- 
tively in  treating  underground  insects. 

CARBON  BISULPHIDE  AND  KEROSENE.  —  The  mixture  is  pre- 
pared by  using  1  part  of  carbon  bisulphide,  and  from  5  to  20 
parts  of  kerosene.  The  two  should  be  thoroughly  stirred  before 
being  applied.  The  action  is  similar  to  that  of  the  bisulphide 
of  carbon,  but  the  mixture  is  practically  out  of  use. 

i  Akhbar,  1857,  Oct.  16.     Cited  in  Gard.  Chron.  1858,  Aug.  28,  653. 
»  Cornell  Agric.  Exp.  St&.  1894,  Bull.  78. 


136  The  Spraying  of  Plants. 

CHLORIDE  OF  COPPER.     See  COPPER  CHLORIDE. 

CHLORIDE  OF  IRON.     See  IRON  CHLORIDE. 

CLAY.     See  WASHES. 

COAL  TAR.  —  If  a  few  quarts  of  coal  tar  are  added  to  a  barrel 
of  water,  the  liquid  soon  becomes  so  impregnated  with  the  odor 
that  it  may  be  used  as  a  repellent  of  insects.  A  strong  solution 
of  gas  tar  may  be  used  for  a  similar  purpose,  but  these  applica- 
tions possess  comparatively  little  value. 

COMBINATIONS  OF  INSECTICIDES  AND  FUNGICIDES.  —  The 
most  successful  of  these  combinations  is  that  of  the  Bordeaux 
mixture  and  compounds  of  arsenic.  The  lime  in  the  mixture 
prevents  the  arsenic  from  injuring  foliage,  while  it  does  not 
appear  to  lessen  the  efficiency  of  the  poison.  Each  preparation 
is  applied  at  the  same  rate  as  if  used  alone. 

A  combination  of  the  ammoniacal  carbonate  of  copper  and 
an  arsenite  has  been  used  with  success  by  some,  but  such  a 
preparation  is  frequently  very  injurious  to  foliage,  and  it 
should  be  applied  with  caution.  The  ammonia  acts  as  a 
solvent  of  the  arsenic,  and  this  solution  does  the  damage. 
The  addition  of  lime  would  tend  to  reduce  the  severity  of 
the  injury. 

The  Bordeaux  mixture  has  been  used  as  an  agent  for  emulsi- 
fying kerosene,  with  apparently  satisfactory  results.1  The 
preparation  should  be  more  thoroughly  tested  before  it  can 
be  recommended.  Kerosene  emulsion  and  Bordeaux  mixture 
have  been  combined,  but  not  with  satisfactory  results.  See 
also  CORNELL  MIXTURE. 

When  pure  kerosene  is  emulsified  with  the  Bordeaux  mixture, 
the  combination  allows  the  addition  of  Paris  green,  making 
a  mixture  adapted  to  destroy  nearly  all  the  insect  and  fungous 
enemies  of  plant  life.  When  a  mixture  of  kerosene  emulsion 
and  the  Bordeaux  mixture  is  made,  the  arsenite  cannot  be 
added  successfully;  for  even  when  the  emulsion  and  the  arsen- 
ite are  united,  the  resulting  mixture  is  still  unsatisfactory. 

Resin  washes  and  kerosene  emulsion,  applied  together,  have 
not  yet  been  sufficiently  studied  and  tested  to  determine  the 
value  of  such  mixtures. 

A  simple  solution  of  resin,  made  as  described  on  page  169,  is 

1  See  Galloway,  Insect  Life,  vii.  126,  for  an  account  of  this  and  other  com- 
binations. 


Materials  and  Formulas.  137 

said  to  increase  the  adhesive  power  of  the  Bordeaux  mixture 
when  the  two  are  applied  together. 

The  resin  preparations  and  arsenical  compounds  have  been 
successfully  united  and  applied,  but  such  combinations  are  at 
present  little  used. 

COPPER  ACETATE;  VERDET;  VERDIGRIS.  —  There  are  sev- 
eral compounds  of  copper  and  acetic  acid,  but  the  one  which 
has  been  used  in  spraying  is  known  as  the  dibasic  acetate  of 
copper.  It  possesses  only  fairly  good  fungicidal  properties,  but 
it  has  been  highly  recommended  for  its  adhesion  to  foliage.  It- 
may  be  applied  at  the  rate  of  2  to  4  ounces  in  about  25  gallons 
of  water. 

COPPER  ARSENITE.     See  SHEELE'S  GREEN,  page  1£0. 

COPPER  CARBONATE;  CARBONATE  OF  COPPER;  CuCO3.  — 
Chester's  method  of  preparing  this  chemical  is  as  follows: 
"Dissolve  in  a  barrel  25  pounds  of  copper  sulphate  in  hot 
water.  In  another  barrel  dissolve  30  pounds  of  sal-soda. 
Allow  both  solutions  to  cool,  then  slowly  pour  the  solution  of 
sal-soda  into  the  copper  sulphate  solution,  stirring  the  same. 
Fill  the  barrel  with  water  and  allow  the  precipitate  of  copper 
carbonate  to  settle.  Upon  the  following  day  siphon  off  the 
clear  supernatant  liquid,  which  contains  most  of  the  injurious 
sodium  sulphate  in  solution.  Fill  the  barrel  again  with  water, 
and  stir  the  precipitate  vigorously  into  suspension  ;  again  allow 
the  precipitate  to  settle,  and  again  on  the  following  day  siphon 
off  the  clear  liquid.  The  operation  washes  the  carbonate  free 
of  most  of  the  sodium  sulphate  which  contaminates  it.  Make 
a  filter  of  stout  muslin,  by  tacking  the  same  to  a  square  wooden 
frame  which  will  just  fit  over  the  open  top  of  the  second  barrel, 
letting  the  muslin  hang  down  loosely  so  as  to  form  a  sack; 
through  this  filter  the  precipitate,  so  as  to  drain  off  the  excess 
of  water,  and  as  the  filter  fills  remove  the  precipitate,  and  allow 
it  to  dry  in  the  air,  when  it  is  ready  for  use.  The  operation 
is  not  troublesome,  and  can  be  carried  on  in  connection  with 
other  work."1  The  following  reactions  are  at  present  supposed 
to  take  place  when  the  two  solutions  are  united:2  12  (CuSO4, 
5H9O)-fl2  (Xa9CO3,  10H0O)  =  6  [CuCO3,  Cu(OH)2,  H2O]  + 
12  Na2  SO4+  6  CO3  +  168  H2O. 


i  Ann.  Bepl.  U.  S.  Com.  Agric.  1890,  403. 

»  Del.  Agric.  Exp.  Sta.  kth  Ann.  Kept.  1891,  67. 


138  The  Spraying  of  Plants. 

By  using  the  above  amounts  of  material,  there  will  be  formed 
a  trifle  over  12  pounds  of  the  carbonate  of  copper,  the  selling 
price  of  which  is  about  forty  cents  a  pound.  When  thus  made 
at  home,  the  cost  is  only  about  fifteen  cents,  which  is  a  great 
saving,  especially  as  the  material  is  nearly  chemically  pure. 

Copper  carbonate  is  a  fine,  bluish-green  powder,  insoluble  in 
water.  It  dissolves  readily  in  ammonia,  forming  the  ammoni- 
acal  solution  of  copper  carbonate,  which  see.  The  powder 
has  often  been  used  as  a  fungicide  when  suspended  in  water, 
but  the  results  obtained  have  almost  invariably  been  unsatisfac- 
tory. When  applied  in  this  manner,  however,  the  following 
formula  will  prove  most  satisfactory : 

Copper  carbonate 1  pound. 

Water 40  gallons. 

The  liquid  should  be  agitated  frequently  to  prevent  the  cop- 
per compound  from  settling  to  the  bottom.  The  cost  of  copper 
carbonate  varies  from  thirty-five  to  sixty  cents  per  pound. 

COPPER  CARBONATE,  AMMONIACAL  SOLUTION  ;  CUPRAM.  — 
Penny1  has  made  a  very  careful  study  of  the  best  method  of 
preparing  this  solution,  and  the  results  of  his  work  are  here 
given  in  full: 

"The  practical  directions  then  are  these:  To  1  volume  of 
26°  Beaume  ammonia  (the  strong  ammonia  of  commerce)  add 
from  7  to  8  volumes  of  water.  Then  add  copper  carbonate, 
best  in  successive  quantities,  until  a  large  portion  remains  un- 
dissolved.  The  mixture  should  be  vigorously  agitated  during 
the  solution  and  finally  allowed  to  subside,  and  the  clear  liquid 
poured  off  from  the  undissolved  salt.  A  second  portion  should 
then  be  made  by  treating  the  residue  of  the  former  lot  with 
more  ammonia  diluted  as  before,  then  with  the  addition  of 
fresh  copper  carbonate,  in  every  case  with  vigorous  stirring  or 
agitation.  This  method  of  making  in  successive  lots  will  result 
in  a  richer  solution  of  copper,  at  least,  unless  an  unwarranted 
length  of  time  be  taken.  This  solution  may  be  made  in  any 
suitable  wooden  or  stoneware  vessel. 

"A  still  better  way  is  to  place  in  a  large  jar  an  inverted 

1  The  chemistry  of  this  solution  has  been  thoroughly  treated  by  C.  L.  Penny,  of 
the  Del.  Agric.  Exp.  Sta.  an  account  of  which  may  be  found  in  Bull.  22.  I  have 
also  quoted  freely  from  other  bulletins  of  the  same  station  on  these  subjects. 


Materials  and  Formulas.  139 

crock,  or  other  suitable  shelf,  and  on  this  the  copper  carbonate, 
so  that  it  shall  be  at  the  surface  of  the  ammonia  when  it  is 
poured  in.  After  adding  the  ammonia,  diluted  as  above,  the 
whole  should  be  allowed  to  stand  covered  some  time,  as  over 
night,  and  then  the  un dissolved  copper  salt  may  be  in  great 
part  easily  lifted  out  of  the  solution.  Instead  of  the  shelf  a 
suitable  receptacle  may  be  used,  as  a  fine  wire  sieve.  The  jar 
will  need  nothing  but  a  loose  cover,  as  the  loss  of  ammonia  will 
be  slight  at  that  degree  of  dilution. 

"  The  clear  solution  thus  obtained,  containing  from  3  to  4  per 
cent  of  ammonia  gas,  must  be  diluted  as  described  above,  in  no 
case  less  than  13  or  15  fold,  better,  for  the  safety  of  the  plant, 
20  fold  or  more. 

"  Those  directions  which  recommend  so  much  ammonia  (what- 
ever it  may  be)  to  be  used  as  may  be  necessary  to  dissolve  the 
copper  salt  and  then  to  dilute  to  a  given  number  of  gallons,  are 
not  only  not  economical,  but  absolutely  dangerous,  inasmuch  as 
it  is  an  uncertainty  just  how  much  ammonia  may  be  used  in 
the  first  instance,  and  hence  uncertain  what  strength  it  may 
have  after  dilution,  when  applied  to  the  trees.  It  should  be 
borne  in  mind  always  that  if  strong  ammonia  is  used  it  must 
be  diluted  from  first  to  last  at  least  100  fold,  and  better  con- 
siderably more. 

"  The  solubility  of  copper  carbonate  in  ammonium  carbonate 
has  been  studied  but  not  yet  sufficiently  for  report." 

After  the  copper  carbonate  has  been  dissolved  in  ammonia 
water,  it  should  be  used  by  taking  as  much  of  the  fluid  as  con- 
tains 1  ounce  of  dissolved  copper  carbonate,  and  this  is  then 
diluted  with  9  gallons  of  water.  These  proportions  should  be 
retained  when  either  larger  or  smaller  quantities  of  the  fungi- 
cide are  desired. 

The  ammoniacal  solution  of  copper  carbonate  possesses  some 
decided  advantages.  It  is  a  clear  solution  entirely  free  from 
sediment,  and  can  therefore  be  applied  as  readily  as  water. 
Another  favorable  point  is  that  it  may  be  used  quite  freely 
upon  maturing  fruit,  and  also  upon  flowering  plants,  without 
leaving  any  conspicuous  stain.  When  certain  plants  require 
spraying  with  a  fungicide  shortly  before  the  crop  is  harvested, 
this  preparation  is  an  excellent  one  to  use.  In  efficiency  it  also 
ranks  high,  being  clearly  surpassed  in  this  respect  only  by  the 


140  The  Spraying  of  Plants. 

Bordeaux  mixture.     It  is  also  cheap,  and  on  the  whole  is  one  of 
our  most  valuable  remedies. 

Several  definite  formulas  have  been  recommended  for  the 
manufacture  of  this  fungicide,  the  two  following  being  the  best 
known : 

Copper  carbonate 3  ounces. 

Ammonia  (22°  Beaume) 1  quart. 

Agitate  until  the  copper  is  completely  dissolved.  It  will 
keep  indefinitely,  but  should  be  diluted  with  25  gallons  of 
water. 

Copper  carbonate 5  ounces. 

Ammonia  (26°  Beaume) 3  pints. 

"Water 45  gallons. 

The  ammonia  should  be  diluted  as  already  described,  after 
which  the  copper  will  dissolve  more  readily.  Sixty  gallons  of 
water  should  be  used  when  spraying  peaches. 

Combinations  of  the  ammoniacal  carbonate  of  copper  and  the 
arsenites  are  said  to  have  been  used  with  success,  but  my  own 
experiments  have  resulted  differently.  The  combination  injured 
foliage  to  such  an  extent  that  it  was  abandoned  after  repeated 
trials.  When  Paris  green  was  added,  the  mixture  was  par- 
ticularly caustic,  since  the  ammonia  undoubtedly  caused  some 
of  the  arsenic  to  enter  into  solution.  London  purple  did  not 
make  so  caustic  a  mixture,  but  nevertheless  considerable  injury 
resulted,  and  these  combinations  may  be  considered  unsafe. 
The  addition  of  milk  of  lime,'  however,  obviates  the  trouble, 
and  renders  the  preparation  a  safe  one.  Lime  to  the  amount  of 
two  to  three  times  the  bulk  of  the  poison  should  be  added. 

There  are  several  other  mixtures  which,  in  composition,  are 
essentially  the  same  as  the  solution  of  copper  carbonate  in 
ammonia.  They  are  the  modified  eau  celeste,  copper  and  am- 
monium carbonate  mixture,  and  Johnson's  mixture.  Regard- 
ing these,  Chester  says,  "  For  all  practical  purposes,  the  above 
fungicides  of  this  group  are  one  and  the  same,  the  essential 
copper  salt  being,  in  each  case,  what  for  brevity  we  may  call  an 
ammonium  copper  carbonate,  but  which  is  in  reality  a  mixture  of 
ammonium  copper  carbonate  (CuCO3,  2NH3)  and  ammonium 
cupric  hydroxide  [3Cu(OH)2,  4NH3,  3H2O]."  * 

i  Del.  Agric.  Exp.  Sta.  kth  Ann.  Mept.  1891,  68. 


Materials  and  Formulas.  141 

COPPER  CARBONATE  AND  AMMONIUM  CARBONATE  MIXTURE. 
—  This  mixture  was  proposed  by  Chester  in  1890.  He  thought 
it  possible  that  ammonia  might  not  be  the  best  solvent  of 
copper  carbonate  and  the  following  formula  uses  ammonium 
carbonate  in  place  of  ammonium  water.  The  resulting  fun- 
gicide is  nearly  identical  with  copper  carbonate  dissolved  in 
ammonia,  and  the  remarks  regarding  that  fungicide  also  apply, 
in  the  main,  to  this  preparation  : 

Copper  carbonate 3  ounces. 

Ammonium  carbonate 1  pound. 

Water 40-45  gallons. 

"By  this  combination  all  the  copper  is  completely  dissolved. 
To  test  the  question,  I  prepared  the  above  fungicide  with  the 
exception  that  I  took  5  ounces  of  the  copper  carbonate  in  order 
to  have  an  excess.  An  analysis  showed  that  the  1  pound  of 
ammonium  carbonate  had  dissolved  3.11  ounces  of  the  original 
copper  carbonate."1 

Ammonium  carbonate  can  be  bought  for  fifteen  to  thirty 
cents  per  pound. 

COPPERAS.     See  IRON  SULPHATE. 

COPPER  CHLORIDE;  CuCL2.  —  The  chloride  of  copper  has 
received  little  attention  as  a  fungicide,  although  it  is  a  prom- 
ising compound.  It  contains  46.93  per  cent  of  actual  cop- 
per. When  used  alone  it  is  very  caustic  to  foliage,  a  solution 
of  1^  ounces  in  25  gallons  of  water  being  too  strong.  Two 
or  three  times  its  bulk  of  lime  should  be  added,  when  5  ounces 
to  25  gallons  of  water  will  prove  a  satisfactory  proportion.  The 
undissolved  crystals  must  be  kept  in  tightly  closed  glass  vessels, 
as  they  absorb  water  rapidly,  and  are  soon  reduced  to  a  liquid 
condition.  The  chemical  is  at  present  too  expensive  for  general 
use. 

COPPER  SODA  MIXTURE.     See  COPPER  CARBONATE. 

COPPER  SODIUM  HYPOSULPHITE  ;  2  XA2S2O3,  Cu2S2O3.  —  This 
material  may  be  prepared  as  follows  :  "  Dissolve  8  ounces  of  sul 
phate  of  copper  in  hot  water,  then  dilute  with  cold  water,  to  about 
10  gallons.  In  another  vessel  dissolve  1  pound  of  hyposulphite  of 

1  Chester,  Del.  Agric.  Exp.  Sta.  kth  Ann.  Kept.  1891,  71. 
1  For  a  more  complete  discussion  of  this  fungicide,  see  Del.  Agric.  Exp.  Sta 
Itth  Ann.  Rept.  1891,  73. 


142  The  Spraying  of  Plants. 

soda  in  cold  water;  add  the  two  together;  dilute  in  25  gallons." 
The  preparation  possesses  no  special  fungicidal  value. 

COPPER  SULPHATE  ;  SULPHATE  OF  COPPER  ;  BLUE  VITRIOL  ; 
BLUE  STONE;  CuSO4;  CuSO4  +  5H2O. — This  chemical  is  formed 
by  uniting  metallic  copper  and  sulphuric  acid,  the  product  being 
formed  in  several  different  ways.  The  substance  is  deposited 
from  solutions  in  the  form  of  large,  blue,  transparent  crystals 
containing  25.46  per  cent  of  actual  copper,  and  it  is  in  this 
form  that  the  salt  is  commonly  sold.  Granulated  copper  sul- 
phate is  formed  by  breaking  up  the  larger  crystals ;  otherwise, 
it  is  identical  with  the  other  form.  On  account  of  the  fine- 
ness of  the  particles,  the  mass  loses  its  deep  blue  color,  and  for 
this  reason  the  granulated  form  offers  greater  temptations  for 
adulteration.  A  pure  solution  of  copper  sulphate  forms  a  red- 
dish-brown discoloration  with  a  solution  of  the  ferrocyanide  of 
potassium,  and  this  may  be  used  as  a  test  for  the  purity  of  the 
copper  compound. 

Copper  sulphate  is  readily  soluble  in  cold  water,  and  still 
more  so  in  hot  water.  A  solution  may  be  quickly  made  by 
hanging  the  material  in  a  coarse  sack  near  the  surface  of  the 
water.  This  is  done  so  that  the  dissolved  portion  may  settle  to 
the  bottom  as  fast  as  it  enters  into  solution,  for  in  this  manner 
the  crystals  are  continually  surrounded  by  clear  liquid.  If  the 
crystals  are  placed  in  the  bottom  of  the  vessel,  they  are  soon 
surrounded  by  a  saturated  solution  which  prevents  them  from 
being  dissolved  until  the  contents  of  the  vessel  are  stirred  so 
that  the  more  clear  liquid  may  come  in  contact  with  the  crystals. 

Copper  sulphate  should  always  be  dissolved  in  wooden  or 
earthen  vessels.  If  an  iron  vessel  is  used,  the  copper  will  be 
deposited  upon  the  iron,  forming  a  copper-plated  portion 
wherever  the  two  come  in  contact. 

A  simple  solution  of  copper  sulphate  should  be  sparingly 
applied  to  foliage,  for  when  the  liquid  is  sufficiently  concen- 
trated to  have  a  decided  fungicidal  action  it  causes  so  much 
injury  to  most  foliage  that  its  use  cannot  be  considered  safe. 
This  compound  is  more  caustic  than  some  other  forms  of 
copper,  but  Professor  Taft  recommends  the  use  of  a  simple 
solution  of  copper  sulphate  instead  of  ammonia  solution  of 
copper  compounds.  He  has  sucessfully  applied  solutions  con- 
taining 1  part  of  blue  vitriol  in  1000  parts  of  water  to  plants 


Materials  and  Formulas.  143 

whose  foliage  is  not  so  tender  as  that  of  peaches  or  beans.  It  is 
valued  also  because  it  does  not  stain  the  parts  treated.1  On 
dormant  wood  it  can  be  used  freely.  It  is  then  made  of 

Copper  sulphate 1  pound. 

Water 15-25  gallons. 

The  more  dilute  solution  is  for  such  tender  wood  as  peaches. 
Grain  is  often  soaked  in  a  solution  of  copper  sulphate  to  destroy 
spores  of  smut.  The  preparation  is  then  made  of 

Copper  sulphate 1  pound. 

Water 1-2  gallons. 

The  use  of  a  one-half  per  cent  solution  has  been  recom- 
mended for  a  similar  purpose,  the  seed  being  soaked  for  twelve 
or  fifteen  hours. 

COPPER  SULPHATE  AND  SULPHURIC  ACID  SOLUTION.  —  An- 
other, and  a  rather  restricted  use  of  copper  sulphate,  is  to  make 
a  saturated  solution,  and  to  this  add  about  1  per  cent  of  com- 
mercial sulphuric  acid.  The  preparation  is,  of  course,  used 
only  upon  dormant  wrood,  and  is  especially  recommended  for 
anthracnose  of  the  grape. 

The  price  of  copper  sulphate  varies  greatly.  The  granulated 
form  may  be  bought  for  four  to  fifteen  cents  per  pound,  and  the 
crystals  at  four  to  eight  cents. 

COPPER  SULPHATE  AND  AMMONIUM  CARBONATE  MIXTURE. 
—  See  JOHNSON'S  MIXTURE. 

COPPER  SULPHATE,  ANHYDROUS.  —  When  copper  sulphate 
crystals  (CuSO4  +  5  H2O)  are  heated,  the  water  of  crystallization 
is  driven  off  and  only  a  pale  blue  powder  remains  (CuSO4-f 
2  H2O).  This  dissolves  readily  in  water,  and  possesses  the  prop- 
erties of  the  original  crystals,  although  the  weight  is  reduced, 
which  leaves  a  greater  proportionate  amount  of  actual  copper. 
The  powder  has  been  applied  when  mixed  with  sulphur  or  other 
powders  for  the  prevention  of  mildew,  but  it  is  now  little  used. 

CORNELL  MIXTURE.  —  This  preparation  consists  of  a  mixture 
of  Bordeaux  mixture,  kerosene  emulsion,  and  an  arsenical  com- 
pound. The  combination  is  made  with  difficulty,  but  success 
may  follow  if  a  few  points  are  observed.  The  Bordeaux  mix- 
ture must  be  exactly  neutral,  and  here  the  ferrocyanide  of 

1  American  Agriculturist,  middle  edition,  1895,  July  20,  34. 


144  The  Spraying  of  Plants. 

potassium  test  is  of  value.  The  kerosene  emulsion  should  be 
made  according  to  the  Hubbard-Riley  formula,  and  then  be 
poured  into  the  Bordeaux  mixture.  And  finally  the  arsenite 
may  be  added.  Unfortunately,  even  if  the  combination  be 
successfully  made,  the  various  ingredients  appear  to  lose  much 
of  their  value  when  so  applied,  and  as  yet  the  preparation 
cannot  be  generally  recommended.1 

CORROSIVE  SUBLIMATE.     See  MERCURIC  CHLORIDE. 

CUPRAM.  —  A  term  applied  to  copper  carbonate  dissolved  in 
ammonia,  which  see. 

CUPRIC  STEATITE.     See  SULPHOSTEATITE. 

CUPROSTEATITE.  —  Thispowder  closely  resembles  sulphostea- 
tite  in  its  composition,  but  while  the  latter  contains  about  10  per 
cent  of  copper  sulphate,  the  copper  in  cuprosteatite  is  in  the 
form  of  the  hydrate,  about  15  per  cent  of  the  powder  being  of 
this  material.  On  this  account  the  fungicide  is  said  to  be 
less  caustic  to  foliage  than  sulphosteatite.  Both  powders  are 
applied  in  the  same  manner. 

CYANIDE  OF  POTASSIUM.     See  HYDROCYANIC  GAS. 

DALMATIAN  INSECT  POWDER.     See  PYRETHRUM. 

DAVID'S  POWDER;  DRIED  BORDEAUX  MIXTURE.  —  The  old 
formula  for  preparing  the  powder  called  for 

Copper  sulphate 4  pounds. 

Quicklime 16  pounds. 

As  little  water  as  possible  was  used  for  dissolving  the  sul- 
phate and  for  slaking  the  lime ;  the  two  were  then  united  and 
the  product  dried.  It  was  then  ground  to  a  powder  and  ap- 
plied. The  ingredients  used  at  present  in  making  the  Bordeaux 
mixture  can  be  similarly  treated.  When  the  dried  mixture  is 
used  in  place  of  that  suspended  in  water,  it  has  been  found  that 
about  four  times  the  amount  of  the  materials  is  required,  and 
the  distribution  is  on  the  whole  not  so  satisfactory.  The  pow- 
der has  never  been  used  to  any  great  extent,  and  for  the  reasons 
given  will  probably  never  become  popular. 

EAU  CELESTE  (Audoynaud  process). 

Copper  sulphate 1  pound. 

Hot  water 2  gallons. 

1  See  also  Slingerland,  Science,  xxii.  No.  551, 105.  Also,  Bailey,  Annals  Sort. 
1893,  48. 


Materials  and  Formulas.  145 

When  the  crystals  are  dissolved  and  the  liquid  has  cooled,  add 

Ammonia  (22°  Beaume) 1£  pints. 

Water,  to  make 25  gallons. 

This  fungicide  has  a  caustic  action  upon  foliage  and  cannot 
be  recommended  with  safety.  According  to  Professor  Chester, 
"  the  probable  reactions  taking  place  in  the  preparation  of  the 
eau  celeste  are : 1 

1.  3[CuS04,  5H20]   +  4NH4HO 

normal  copper  sulphate  ammonia 

water 

=  CuS04,  2Cu(OH)2  +  2(NH4)2,  SO4  +  15  H20. 

basic  copper 
sulphate 

2.  CuS04,  2  Cu(OH)2  +  2(NH4)2,  SO4  +  8  NH4HO 

In  excess. 

=  3(CuSO4,  4  NH3,  H2O)  +  9  H20." 

ammonium  copper  sulphate 

Nevertheless,  the  fungicide  is  not  a  safe  one  to  use.2 
EMULSIONS.  —  Of  the  insecticides  which  kill  by  contact  there 
are  none  more  effective  than  those  which  are  composed  of  emul- 
sion of  soap  solutions  and  such  penetrating  liquids  as  mineral 
oils.  The  kerosene  emulsions  are  the  best  known  and  most 
generally  used.  (See  under  KEROSENE.)  But  the  following 
liquids  have  been  recommended3  as  suitable  substitutes  for  this 
oil.  The  percentages  of  the  amounts  to  use  in  the  emulsions 
are  given  for  comparison  : 

Benzine  emulsion,  containing  from 0.5  to  2.0  per  cent. 

Kerosene  emulsion,  containing  from 0.5  to  2.0  per  cent. 

"  Nitro  benzina  "  emulsion,  containing  from  . .  0.5  to  0.75  per  cent. 
Bisulphide  of  carbon  emulsion,  containing  from  0.5  to  0.75  per  cent. 

The  general  method  of  procedure  for  preparing  these  emul- 
sions is  as  follows : 

"  Active  principle  (oils,  etc.) 0.5  to   1.0  per  cent- 

Soft  soap 0.5  to   2.0  per  cent. 

Water  of  preparation 1.0  to   3.0  per  cent. 

Water  of  dilution 99.0  to  97.0  per  cent." 

1  Del.  Agric.  Exp.  Sta.  Uth  Ann.  Kept.  1891,  68. 

2  Ferret,  in  Jour.  (TAg.  Prat.  1SS7,  June  23,  878,  says  that  the  precipitate 
first  formed  when  ammonia  is  added  to  a  copper  sulphate  solution  is  a  hydrated 
oxide  of  copper  (oxide  de  cuivre  hydrate).    The  clear  liquid  contains  the  sulphate  of 
ammonia,  which  has  a  tendency  to  injure  foliage. 

3  Ad.  Targioni  Tozzetti,"  Mostra  di  Sostanze  e  di  Emulsion!  Insetticide,"  1691,  IT. 

L 


146  The  Spraying  of  Plants. 

These  ingredients  are  mixed  in  a  definite  order : 

(a)  Dissolve  the  soap  in  the  insecticide. 

(6)  Add  this  solution  to  the  water  of  preparation,  and  agitate. 

(c)  The  water  of  dilution  may  then  be  added,  and  the  emul- 
sion again  thoroughly  agitated. 

In  America  the  method  followed  is  to  dissolve  the  soap  in  the 
"water  of  preparation,"  after  which  the  oil  is  added.  This 
mixture  is  then  thoroughly  agitated,  commonly  by  means  of  a 
force-pump,  until  all  the  oil  is  emulsified.  If  the  liquids  are 
hot,  an  emulsion  may  be  produced  more  easily. 

FERROCYANIDE  OF  POTASSIUM;  YELLOW  PRUSSIATE  OF 
POTASH;  K4FECY6.  —  The  only  value  this  material  possesses  in 
connection  with  spraying  is  to  assist  in  making  the  Bordeaux 
mixture,  and  to  serve  as  a  test  for  discovering  the  presence 
of  sulphate  of  iron.  The  test  solution  may  be  made  by  dis- 
solving the  compound  in  water : 

Ferrocyanide  of  potassium 1  ounce. 

Water 1  pint. 

The  test  solution  forms  a  reddish-brown  precipitate,  or  discol- 
oration (the  ferrocyanide  of  copper,  Cu2FeCyfi),  with  a  dissolved 
copper  salt,  but  a  blue  precipitate  with  an  iron  salt.  See  page 
151. 

FISH-OIL  SOAP.  — 

Crystal  potash  lye 1  pound. 

Fish-oil 3  pints. 

Soft  water 3  gallons. 

Dissolve  the  lye  in  the  water,  and  when  boiling,  add  the  oil, 
and  boil  for  two  hours.  One  pound  of  the  soap  may  be  dissolved 
in  5  to  10  gallons  of  water.  This  is  of  value  as  an  insecticide 

FLOUR.  —  Flour  is  sometimes  added  to  liquids  to  render  them 
more  adhesive.  It  may  be  used  at  the  rate  of  1  pound  to  40 
or  50  gallons  of  the  preparation,  but  such  additions  are  rarely, 
if  ever,  advisable.  An  exception  may  be  made  in  the  case  of 
powders,  especially  those  containing  the  arsenites.  With  these, 
the  addition  of  flour,  at  the  rate  of  five  to  ten  times  the  bulk  of 
the  poison,  may  be  of  service  in  rendering  the  mixture  more  ad- 
herent to  the  foliage.  But  this  condition  is  often  followed  by 


Materials  and  Formulas.  147 

serious  injury,  undoubtedly  due  to  the  fact  that  the  poison  is 
not  washed  off,  but  remains  to  burn  the  foliage.  The  addition 
of  lime  to  the  mixture  would  probably  be  beneficial. 

FOSTITE.     See  SULPHOSTEATITE. 

FCMA.  —  A  form  of  carbon  bisulphide,  which  see. 

GAS  TREATMENT.     See  HYDROCYANIC  ACID  GAS. 

GLUE.  —  Glue  is  frequently  recommended  as  a  valuable  addi- 
tion to  insecticides  and  fungicides;  it  is  supposed  to  increase 
their  adhesive  properties,  and  probably  does  so  to  a  limited  ex- 
tent. In  general  practice  its  use  is  unnecessary,  but  in  case 
liquids  do  not  adhere  to  foliage  when  the  application  is  first 
made,  the  addition  of  some  cheap  glue,  used  at  the  rate  of  1 
pound  to  50  gallons  of  liquid,  may  prove  of  value. 

GLUE  AND  ARSENITES. — 

Common  glue 1  pound. 

Paris  green 1  ounce. 

Hot  water 2  gallons. 

The  glue  is  first  dissolved  in  hot  water,  after  which  the 
Paris  green  is  stirred  in,  and  the  remainder  of  the  water  added. 
This  is  said  to  be  of  value  in  protecting  trees  from  borers,  but 
the  applications  may  cause  serious  injury,  and  the  remedy  should 
be  used  cautiously.  The  mixture  may  also  be  used  upon  foliage, 
in  which  case  dilute  with  about  15  gallons  of  water. 

GRISON  LIQUID  ;  EAU  GRISON  ;  SULPHUR  AND  LIME  MIX- 
TURE.—  For  the  original  formula  of  this  liquid,  see  page  16. 
It  is  at  present  commonly  made  by  using 

Flowers  of  sulphur 3  pounds. 

Quicklime 3      " 

Water , 6  gallons. 

These  should  be  boiled  until  the  amount  of  liquid  is  reduced 
to  2  gallons.  It  should  then  be  allowed  to  settle,  and  the  clear 
liquid  be  drawn  off  and  tightly  corked  in  bottles.  Dilute  with 
100  parts  of  water  before  using.  The  preparation  is  particu- 
larly valuable  in  treating  the  European  mildew  of  the  grape, 
and  also  for  use  against  various  mildews  which  attack  plants 
grown  under  glass.  See,  also,  LIME  SULPHIDE. 

GYPSIXE.     See  ARSENATE  OF  LEAD. 


148  The  Spraying  of  Plants. 

HELLEBORE  ;  WHITE  HELLEBORE  ;  EUROPEAN  HELLEBORE  ; 
VERATRUM  ALBUM.  —  The  roots  of  this  plant  and  also  of 
Veratrum  viride,  American  hellebore,  when  ground  into  a  pow- 
der possess  considerable  insecticidal  value.  The  powder  is  of  a 
light  yellowish-brown  color,  and  possesses  an  odor  which  is  not 
wholly  disagreeable.  The  active  principle  of  the  root,  known  as 
Jervine,  is  a  very  powerful  alkaloid.  It  generally  destroys 
an  insect  by  being  eaten  with  the  food,  but  it  appears 
probable  that  it  also  possesses  a  certain  value  when  it  merely 
comes  in  contact  with  the  insect's  body.  Hellebore  is  much 
less  poisonous  than  the  arsenical  compounds,  and  it  also  soon 
loses  its  strength  when  exposed  to  the  air.  For  these  reasons  it 
should  be  preferred  to  the  mineral  poisons  when  the  plants  to  be 
treated  are  bearing  products  which  are  nearly  ready  for  market, 
as  ripening  currants,  or  heading  cabbages.  If  properly  applied, 
it  is  very  effective  in  destroying  chewing  insects,  and  more  than 
two  applications  are  rarely  necessary.  Only  the  fresh  powder 
should  be  used.  It  may  be  applied  either  in  dry  form  or  when 
mixed  with  water.  When  used  in  the  form  of  a  dry  powder,  it 
is  generally  applied  pure,  but  may  be  successfully  diluted  with 
once  or  twice  its  bulk  of  plaster,  lime,  or  flour,  the  last  causing 
it  to  adhere  more  firmly  to  the  foliage.  In  cases  where  the 
insect  does  not  yield  readily  to  treatment,  applications  of  the 
pure  powder  may  be  advisable.  The  powder  should  be  sifted 
uniformly  upon  the  foliage. 

When  used  in  water  the  following  formula  may  be  success- 
fully employed : 

Hellebore  (fresh) 1  ounce. 

Water 3  gallons. 

Some  recommend  the  addition  of  an  ounce  of  glue  to  the 
above  mixture,  or  a  small  amount  of  flour,  in  order  to  render  it 
more  adhesive ;  yet  for  general  practice  such  additions  are 
scarcely  necessary.  The  use  of  one  ounce  of  powdered  soapstone 
with  the  mixture  of  hellebore  and  water  has  also  been  recom- 
mended as  possessing  especial  value.  The  cost  of  good  hellebore 
varies  from  twelve  to  twenty-five  cents  per  pound. 

HOT  WATER.     See  WATER. 

HYDROCYANIC  ACID  GAS  ;  HCN.  —  D.  W.  Coquillet  was 
the  first  to  suggest  and  use  this  gas  for  the  destruction  of  scale 


Materials  and  Formulas. 


149 


insects.  His  experiments  began  in  September,  1886,  in  the 
orange  grove  of  J.  W.  Wolfskill,  of  Los  Angeles,  Cal.  Its 
use  has  been  followed  by  such  good  results  that  all  other  gases 
have  been  abandoned  in  treating  these  pests.  The  gas  is  pre- 
pared by  using 

Cyanide  of  potassium,  60  per  cent 1  ounce. 

Commercial  sulphuric  acid 1  fluid  ounce. 

Water 3    "     ounces. 

Potassium  cyanide  of  90  per  cent  has  also  given  excellent 
results.  The  water  is  first  placed  in  an  open,  glazed  vessel, 
and  then  the  acid  is  added.  When  the  parts  to  be  treated  are 
all  covered,  the  diluted  acid  is  placed  under  the  tent,  the  cya- 
nide of  potassium  is  dropped  in,  and  the  tent  immediately 
closed.  The  gas  is  exceedingly  poisonous,  and  should  not  be 
inhaled.  The  amount  formed  with  the  above  materials  is  suffi- 
cient for  a  confined  space  containing  150  cubic  feet.  It  is  safer 
to  use  the  gas  upon  dormant  trees,  and  during  cool  weather  or  at 
night,  since  trees  are  more  easily  injured  during  a  high  tempera- 
ture. The  treated  parts  should  remain  covered  about  an  hour. 

"  The  following  table,  giving  height  of  trees  and  the  propor- 
tions of  chemicals  and  water,  will  be  found  suitable  for  districts 
in  the  interior  or  beyond  ten  miles  in  a  direct  line  from  the  sea- 
coast  : 


Height  of  Tree 
—  Feet. 

Diameter 
through  Foli- 
age —  Feet. 

Water  —  Fluid 
Ounces. 

Sulphuric  Acid 
—  Fluid  Ounces. 

Cyanide  of 
Potassium  — 
Ounces. 

6 

4 

2 

1 

1 

8 

6 

4 

2 

2 

10 

8 

6 

3 

3 

12 

10 

10 

5 

5 

12 

14 

14 

7 

7 

14 

14 

16 

8 

8 

16 

16 

18 

9 

9 

18 

16 

20 

10 

10 

20 

16 

22 

11 

11 

22 

18 

24 

12 

12 

24 

20 

26 

13 

13 

26 
30 

20 
20 

27 

28 

13* 
14 

13* 
14 

150  The  Spraying  of  Plants. 

"  One  would  suppose  that  an  [orange]  tree  having  a  dense 
foliage  would  fill  up  the  space  within  the  tent  and  require  less 
gas  to  be  effective.  But  the  cold  surface  of  the  leaves  con- 
denses the  gas,  and  fumigators  find  that  a  slightly  heavier 
charge  of  chemicals  is  necessary  for  such  a  tree,  and  where  the 
foliage  is  scant  a  less  amount  than  is  given  in  the  table  will 
answer.  Some  orchardists  and  fumigators  consider  that  the 
work  has  not  been  effective  unless  some  of  the  leaves  or  tender 
twigs  have  been  injured.  This  is  not  necessary,  for  in  our 
early  experiments  we  have  treated  trees  and  killed  the  scale 
without  even  injuring  the  most  tender  twig  or  blossom.  As 
the  trees  recover  very  quickly,  even  when  seriously  scorched,  a 
slight  burning  is  no  detriment  and  is  evidence  that  the  work 
has  been  effective,  except  in  the  case  of  '  black  scale '  (Lecanium 
Olece),  during  the  early  summer  when  the  eggs  are  under  the 
females.  The  proper  time  to  fumigate  for  this  scale  is  during 
the  fall  or  early  winter,  when  they  are  in  the  larva  state." 1 

"  In  order  to  make  the  canvas  used  for  fumigation  perfectly 
air-tight,  to  prevent  the  gas  escaping,  the  tents  have  been 
treated  with  a  light  coat  of  boiled  linseed  oil.  The  great 
objection  to  the  oil  has  been  that  it  had  a  tendency  to  stiffen 
the  canvas  and  add  considerably  to  its  weight,  so  a  cheaper 
and  more  flexible  preparation  was  sought.  The  following 
mixture,  used  by  Commissioner  Scott,  of  Los  Angeles  County, 
[Cal.]  during  the  past  season,  made  the  tents  gas-tight  and 
left  the  canvas  soft  and  pliable.  The  chief  essential  ingredient 
is  a  supply  of  common  prickly-pear  cactus  (Opuntia  Engelmanni) 
that  grows  in  abundance  in  the  southern  counties  of  the  state. 
It  is  the  flat-leaf  species,  and  parties  living  in  sections  to  which 
it  is  not  indigenous  could  have  it  sent  in  boxes.  To  make  the 
cactus  extract,  chop  up  enough  cactus  to  fill  a  barrel  two-thirds 
full,  then  fill  up  the  barrel  with  cold  water.  It  should  stand 
for  twenty-four  hours,  when  it  will  be  ready  for  use.  Do  not 
prepare  more  than  is  required  for  immediate  use,  otherwise  it 
will  sour  and  become  worthless.  Stir  well,  then  strain  ten  gallons 
of  the  liquid  into  another  tub  or  barrel ;  dissolve  twro  pounds  ot 
common  glue  and  add  to  the  cactus  extract,  with  sufficient 
yellow  ochre  or  Venetian  red  to  give  it  a  good  body.  After 
thoroughly  mixing  the  ingredients,  it  is  ready  for  use.  Both 

i  Craw,  California  State  Ed.  of  Hort.  1894,  Bull.  68,  18. 


Materials  and  Formulas.  151 

sides  of  the  canvas  should  be  painted,  and  the  dressing  well 
rubbed  into  the  fiber  with  a  flat  paint-brush.  If  oil  is  used, 
the  canvas  should  be  spread  out  and  thoroughly  dried  before  it 
is  rolled  up,  or  it  is  liable  to  be  destroyed  by  spontaneous  com- 
bustion. When  dry  there  is  no  danger  from  this."1 

IRON  CHLORIDE  (probably  FERROUS  CHLORIDE,  FECL2).  — 
This  material  has  been  successfully  used  in  checking  certain 
coffee  diseases,  and  its  use  appears  to  be  restricted  almost 
entirely  to  this  plant.  Very  dilute  solutions  were  applied,  and 
these  proved  to  be  exceedingly  adhesive.  The  remedy  is  at 
present  little  known. 

IRON  SULPHATE;  COPPERAS;  GREEN  VITRIOL;  FESO4.— 
Copperas  is  formed  by  the  union  of  sulphuric  acid  and  iron. 
It  is  a  green  crystalline  substance,  and  when  finely  broken  up  it 
bears  a  certain  resemblance  to  granulated  copper  sulphate,  and 
as  it  is  much  cheaper  than  the  latter,  it  has  been  used  as  a 
means  of  adulterating  the  copper  salt.  Iron  sulphate  dissolves 
readily  in  water.  The  ferrocyanide  of  potassium  may  be  used 
as  a  means  of  detecting  the  presence  of  this  compound.  This 
test  gives  a  reddish-brown  precipitate  with  a  concentrated  solu- 
tion of  copper  sulphate,  but  with  a  dilute  solution  it  merely 
gives  the  same  color  to  the  liquid,  without  the  formation  of  a 
precipitate.  With  the  sulphate  of  iron,  the  test  forms  a  deep 
blue  precipitate,  very  easily  distinguished.  If  there  is  any  ques- 
tion as  to  the  purity  of  copper  sulphate,  this  test  may  easily  be 
used  and  the  adulteration  detected,  provided  the  sulphate  of 
iron  has  been  used  as  an  adulterant. 

Iron  sulphate  is  of  no  practical  value  as  an  insecticide,  and 
its  use  as  a  fungicide  is  very  limited.  Iron  is  not  nearly  so 
efficient  in  this  respect  as  copper  is,  so  the  latter  is  almost 
invariably  preferred  except  when  the  plants  to  be  treated  are 
dormant.  The  iron  salt  may  then  be  used  as  follows : 

Iron  sulphate 4-8  pounds. 

Water 1  gallon. 

All  parts  should  be  thoroughly  treated  writh  this  solution; 
but  the  value  of  the  operation  has,  in  most  cases,  still  to  be 
determined. 

*  Craw,  California  State  £d.  of  Sort.  1894,  Bull.  68,  20. 


152  The  Spraying  of  Plants. 

Against  anthracnose  of  the  grape  the  following  application 
has  shown  itself  to  be  of  great  value,  and  it  is  regularly  used 
by  European  vineyardists  : 

Water  (hot) 100  parts. 

Iron  sulphate,  as  much  as  the  water  will  dis- 
solve. 
Sulphuric  acid 1  part. 

Great  care  should  be  exercised  in  using  this  preparation,  as 
it  is  exceedingly  caustic  and  will  injure  machinery,  clothes,  and 
nearly  everything  with  which  it  comes  in  contact.  It  is  gener- 
ally applied  with  a  swab  made  by  tying  rags  about  the  end  of 
a  stick.  Dormant  vines  are  uninjured  by  the  treatment. 

JOHNSON'S  MIXTURE;  COPPER  SULPHATE  AND  AMMONIUM 
CARBONATE  MIXTURE.  —  This  preparation  is  almost  identical 
with  the  modified  eau  celeste,  ammonium  sulphate  being  formed 
by  the  reactions  instead  of  sodium  sulphate.  The  former  is 
injurious  to  foliage,  and  for  this  reason  the  mixture  never  has 
been  used  to  any  extent.  It  contains  dissolved  copper  carbon- 
ate, as  does  the  ammonia  solution  of  the  same  compound,  and 
that  fungicide  should  be  consulted  in  connection  with  John- 
son's mixture. 

Copper  sulphate 8  ounces. 

Ammonium  carbonate 1  pound. 

Dissolve  in  a  pail  of  warm  water  and  then  dilute  with 
Water 25  gallons. 

KEROSENE;  COAL  OIL;  (PETROLEUM).  —  Kerosene  has  been 
used  to  destroy  insects  almost  from  the  time  of  its  first  general 
introduction  for  illuminating  purposes.  It  was  originally  used 
in  two  ways :  first,  when  pure,  in  which  case  it  was  carefully 
used  and  applied  as  much  as  possible  only  to  the  insects  to  be 
destroyed;  and  second,  when  mixed  with  water,  generally  at 
the  rate  of  1  gill  to  1  or  2  gallons  of  water.  Since  the  oil  is 
lighter  than  water,  such  mixtures  were  imperfect,  and  a  certain 
amount  of  skill  was  required  to  obtain  a  mixture  sufficiently 
uniform  to  prevent  injury  to  the  foliage.  A  small  hand-syringe 
was  the  instrument  generally  employed,  but  now  special  ma- 
chinery has  been  devised  for  the  same  purpose.  Such  appli- 


Materials  and  Formulas.  153 

cations  are  still  made,  but  to  a  limited  extent.  Most  plants 
are  easily  injured  by  the  oil.  Coleus,  grape,  peach,  pea,  and 
eggplant  appear  to  suffer  less  than  others.  Paraffine,  a  closely 
related  product,  may  be  used  at  the  rate  of  a  wineglassf  ul  to 
a  watering-can  of  water,  the  mixture  being  sprayed  upon  the 
insects. 

Pure  kerosene  will  destroy  trees  and  branches  which  are  sev- 
eral years  old  if  a  sufficient  amount  of  the  oil  be  applied.  The 
beneficial  results  of  such  treatment  are  open  to  doubt,  and  the 
practice  can  hardly  be  advised  except  in  isolated  cases,  when 
some  unusual  danger  is  feared.  Howard  has  found  that  the  oil 
may  be  used  to  advantage  in  the  destruction  of  the  mosquito. 
These  breed  in  stagnant  water,  such  as  is  commonly  found 
in  pools,  etc.,  and  by  the  use  of  1  ounce  of  oil  to  15  square 
feet  of  water  surface,  a  film  is  formed  which  is  very  effectual 
in  destroying  all  forms  of  aquatic  insect  life. 

KEROSENE  AND  MILK  EMULSIONS.  —  By  emulsifying  kero- 
sene with  some  other  material  a  very  uniform  dilution  of  the 
oil  may  be  obtained,  and  it  may  be  used  of  any  desired  strength. 
Milk  has  been  very  extensively  used  as  an  emulsifying  agent, 
and  it  possesses  particular  value  in  those  regions  in  which  it  is 
difficult  to  obtain  soft  water,  hard  water  being  unsuited  to 
assist  in  making  emulsion  when  soap  is  used  instead  of  milk. 

Kerosene  and  Condensed  Milk  Emulsion.  — 

Kerosene 2  gallons. 

Condensed  milk 3  pints. 

Water 6     " 

It  is  unnecessary  to  heat  the  ingredients,  but  they  may  be 
mixed  and  immediately  churned  or  agitated  by  means  of  a 
force-pump  until  a  perfect  emulsion  is  obtained. 

Kerosene  and  Sour  Milk  Emulsion.  — 

Kerosene 2  gallons. 

Sour  milk 1  gallon. 

These  liquids  should  be  agitated  in  the  same  manner  as  the 
preceding.  The  mixture  will  soon  assume  a  thick  buttery  con- 
sistency, and  when  the  entire  mass  is  in  this  condition  the  oil  is 
properly  emulsified.  The  addition  of  a  little  vinegar  is  said  to 
hasten  the  process,  especially  if  the  milk  is  sweet  instead  of 


154  The  Spraying  of  Plants. 

sour.  If  sweet  milk  is  used,  the  emulsion  is  not  formed  so 
readily,  but  in  other  respects  the  two  are  equally  valuable.  If 
the  applications  are  not  to  be  made  immediately,  it  is  better  to 
put  the  concentrated  emulsion  in  air-tight  jars  until  wanted, 
otherwise  fermentation  will  take  place,  and  after  a  week  or 
more  the  preparation  will  be  of  little  value. 

These  emulsions  should  be  diluted  fifteen  or  twenty  times 
with  water,  depending  upon  the  insect  to  be  destroyed  and  the 
foliage  to  be  treated. 

KEROSENE  AND  SOAP  EMULSIONS.  —  Soap  is  very  generally 
preferred  to  milk  for  emulsifying  kerosene  and  other  oils. 
Hard  soap  is  easily  obtained,  and  is  therefore  more  commonly 
used.  Whale-oil  soap  is  said  to  be  the  best  for  this  purpose. 
If  soft  soap  is  at  hand,  it  may  be  used  as  well  as  the  hard  soaps, 
since  the  actions  of  the  two  are  practically  identical.  One  quart 
of  soft  soap  is  considered  to  be  the  equivalent  of  one-fourth  pound 
hard  soap. 

Cook's  Soft  Soap  Emulsion.  —  "Dissolve  one  quart  of  soft 
soap  in  two  quarts  of  boiling  water.  Remove  from  the  fire, 
and,  while  still  boiling  hot,  add  one  pint  of  kerosene  and  im- 
mediately agitate  with  the  pump  as  described  above.  In  two 
or  three  minutes  the  emulsion  will  be  perfect.  This  should 
be  diluted  by  adding  an  equal  amount  of  water,  when  it 
is  ready  for  use.  This  always  emulsifies  readily  with  hard  or 
soft  water ;  always  remains  permanent,  for  years  even ;  and  is 
very  easily  diluted,  even  in  the  coldest  weather,  and  without 
any  heating.  In  this  last  respect  it  has  no  equal,  so  far  as  we 
have  experimented.  The  objections  to  it  are :  we  cannot 
always  procure  the  soft  soap,  though  many  farmers  make  it, 
and  it  is  generally  to  be  found  in  our  markets;  it  occasionally 
injures  the  foliage,  probably  owing  to  the  caustic  properties  of 
the  soap.  We  have  used  this  freely  for  years  and  never  saw 
any  injury  till  the  past  season.  In  case  of  any  such  trouble  we 
may  use  only  half  the  amount  of  soap  —  one  pint  instead  of  one 
quart."  The  emulsion  should  be  diluted  so  that  about  one- 
fifteenth  of  the  liquid  is  kerosene,  the  amount  varying  under 
different  circumstances. 

Cook's  Hard  Soap  Emulsion.  —  "  Dissolve  one-fourth  pound  of 
hard  soap,  Ivory,  Babbitt,  Jaxon,  or  whale-oil,  etc.,  in  two 
quarts  of  water,  add,  as  before,  one  pint  of  kerosene  oil,  and 


Materials  and  Formulas.  155 

pump  the  mixture  back  into  itself  while  hot.  This  always 
emulsifies  at  once,  and  is  permanent  with  hard  as  well  as  soft 
water.  This  is  diluted  with  twice  its  bulk  of  water  before  use. 
The  objection  to  a  large  amount  of  water  sinks  before  the  fact 
that  this  secures  a  sure  and  permanent  emulsion,  even  though 
diluted  with  hard  water.  This  also  becomes,  with  certain 
soaps,  lumpy  and  stringy  when  cold,  so  that  it  cannot  be 
readily  diluted  with  cold  water  unless  first  heated.  Yet  this  is 
true  with  all  hard  soap  emulsions  in  case  of  certain  soaps.  We 
can,  however,  always  dilute  easily  if  we  do  so  at  once  before  the 
emulsion  is  cold,  and  we  can  also  do  the  same  either  by  heating 
an  emulsion  or  diluent,  no  matter  how  long  we  wait."  (Page  81). 
Hublard-Riley  Kerosene  Emulsion.  — 

Hard  soap \  pound. 

Kerosene 2  gallons. 

Boiling  soft  water 1  gallon. 

The  soap  should  first  be  dissolved  in  the  boiling  water,  after 
which  the  kerosene  is  added,  and  the  two  churned  for  five  or  ten 
minutes.  One  essential  condition  of  success  in  making  this 
emulsion  is  that  the  liquids  should  be  as  warm  as  possible.  My 
own  practice  has  been  to  heat  the  two  after  the  kerosene  has 
been  added,  taking  care  that  the  oil  did  not  catch  fire.  It  is 
also  necessary  that  the  water  be  as  soft  as  possible,  for  if  much 
mineral  matter  is  present  the  emulsion  will  not  be  permanent, 
and  the  oil  will  soon  separate  and  rise  to  the  surface.  With 
very  hard  water  it  is  almost  impossible  to  obtain  a  good  emul- 
sion. 

If  these  conditions  are  all  fulfilled,  however,  this  emulsion  is 
an  excellent  one,  as  the  amount  of  kerosene  used  is  large,  and 
in  other  respects  the  preparation  is  easily  handled.  It  should 
be  diluted  with  from  4  to  20  parts  of  water  before  being  ap- 
plied, hard  water  being  again  avoided.  When  diluted  with  4 
parts  of  water,  the  emulsion  contains  about  29  per  cent  of  kero- 
sene ;  when  diluted  with  20  parts  of  water  it  contains  nearly 
9  per  cent  of  the  oil. 

KEROSENE  EMULSION  AND  ARSENITES.  —  The  attempt  has 
frequently  been  made  to  obtain  a  uniform  mixture  of  these  two 
materials,  but  with  only  partial  success.  The  results  have  not 
been  satisfactory,  and  the  use  of  such  a  mixture  cannot  be  ad- 


156  The  Spraying  of  Plants. 

vised  since  the  arsenicals  and  a  certain  amount  of  the  emulsion 
appear  to  separate  in  the  form  of  clots  that  adhere  with  surpris- 
ing firmness  to  the  sides  of  the  vessel  in  which  the  preparation 
is  made,  and  render  its  use  practically  impossible. 

KEROSENE  EMULSION  AND  BALSAM  OF  FIR.  —  The  addi- 
tion of  two  ounces  of  fir  balsam  to  the  Hubbard-Riley  emul- 
sion is  said  to  increase  its  efficiency  and  also  its  adhesive 
properties. 

One-half  pint  of  turpentine  may  be  used  for  the  same  pur- 
pose. 

KEROSENE  EMULSION  AND  BORDEAUX  MIXTURE.  —  A  mix- 
ture between  these  two  preparations  may  be  obtained  without 
much  difficulty,  but  the  fungicide  should  be  made  with  as  little 
lime  as  possible.  For  this  purpose,  employ  the  ferrocyanide 
of  potassium  test.  Applications  of  the  mixture  can  scarcely  be 
advised,  however,  since  both  fungicide  and  insecticide  appear  to 
lose  a  certain  degree  of  their  efficiency,  since  such  even  distribu- 
tion on  the  foliage  cannot  be  obtained  as  when  the  two  are 
applied  separately. 

KEROSENE-PYRETHRUM  EMULSION.  —  This  emulsion  is  made 
in  the  same  manner  as  the  preceding  ones,  but  pure  kerosene 
is  not  used.  A  decoction  of  pyrethrum  is  made  by  filtering 
1  gallon  of  the  oil  through  2\  pounds  of  the  powder,  and  this 
decoction  is  then  treated  like  pure  kerosene.  It  is  little  known. 

LEAD  ARSENATE.     See  ARSENATE  OF  LEAD. 

LIME.  —  Quicklime  is  the  most  valuable  form  of  the  metal 
calcium  to  be  used  in  spraying,  although  the  compound  does 
not  remain  in  this  form.  Quicklime  is  the  oxide  of  calcium, 
CaO.  When  water  is  added  to  it,  there  is  formed  the  hydrate 
of  lime,  or  calcium  hydroxide,  Ca(OH)2,  or  water-slaked  lime, 
as  it  is  more  commonly  called.  When  exposed  to  air,  quicklime 
sooner  or  later  combines  with  carbonic  acid  gas  and  is  thus 
converted  into  the  carbonate  of  lime,  or  air-slaked  lime,  CaCO3 ; 
this  is  the  same,  chemically,  as  limestone,  or  chalk. 

The  milk  of  lime  is  formed  by  slaking  quicklime  in  water. 
It  possesses  little  value  when  used  alone,  either  for  combating 
insects  or  fungi,  but  is  extensively  used  to  avert  the  caustic 
action  of  other  preparations.  If  sprayed  upon  plants,  it  may  be 
found  desirable  to  strain  out  the  coarser  particles  to  prevent 
clogging  the  machinery.  Air-slaked  lime  has  been  used  in 


Materials  and  Formulas.  157 

making  the  Bordeaux  mixture,  but  in  that  case  twice  as  much 
lime  should  be  used  as  called  for  by  the  formulas  in  which 
quicklime  is  mentioned.1 

The  action  of  lime  upon  foliage  has  been  studied  by  Cuboni.2 
When  this  material  was  first  used  by  the  Italians,  their  endeavor 
was  to  cover  the  grape  foliage  with  a  thick  and  uniform  layer. 
The  work  of  Cuboni  shows  that  light  acts  upon  the  chlorophyll 
under  the  treated  parts  in  a  perfectly  normal  manner,  for  treated 
leaves  had  a  coefficient  of  transpiration  of  7  grams  per  square 
centimeter  in  one  hour,  while  non-treated  leaves,  under  the 
same  conditions,  had  a  coefficient  of  7.25  grams,  a  very  insig- 
nificant difference.  It  would  thus  appear  that  no  injurious 
influence  of  this  nature  need  be  feared  from  applications  of 
lime  or  of  the  Bordeaux  mixture. 

Quicklime  may  be  applied  alone  as  follows : 

Lime £-2  pecks. 

Water 40  gallons. 

This  formula  allows  of  much  modification,  but  the  thicker 
the  mixture  is  made  the  more  difficult  it  is  to  apply.  Its  value 
as  a  fungicide  rests  largely  in  the  mechanical  action  of  the  lime; 
it  forms  a  coating  over  the  parts  treated,  so  that  the  germinating 
spore  cannot  penetrate  to  the  leaf  tissue.  In  other  respects  its 
effect  is  but  slight. 

Air-slaked  lime  is  of  greater  value  as  an  insecticide  when  used 
dry,  than  when  mixed  with  water.  In  the  dry  condition,  it  is 
effective  in  destroying  snails,  slugs,  and  the  larvae  of  some  insects, 
as  the  cherry  slug.  It  may  also  be  used  as  a  diluent  of  poison- 
ous powders,  as  hellebore,  arsenites,  etc.  It  causes  the  death  of 
angleworms,  whether  used  dry  or  with  water,  and  flower  pots 
may  easily  be  rid  of  them  by  the  use  of  this  material,  a  satu- 
rated solution  containing  sufficient  quantities  for  the  purpose. 

Quicklime  can  be  bought  for  60  cents  to  $1.50  per  barrel. 

LIME,  SALT,  AND  SULPHUR  WASH.  —  A  mixture  similar  to 
the  following  was  originally  used  in  California  as  a  sheep-dip, 
but  as  fruit  trees  began  to  drive  out  the  sheep,  the  applications 
of  the  compound  were  transferred  to  the  trees,  and  thus  it  has 
been  very  generally  used,  and  lias  proved  to  be  of  value  in  the 

1  See,  also,  Millardet  et  Gayon,  Jour,  d  'Ag.  Prat.  1888,  May  17,  693  et  seq. 
>  Cited  by  Viala,  "  Les  Maladies  de  la  Vigne,"  1893,  118. 


158  The  Spraying  of  Plants. 

orchards  as  well  as  on  the  sheep.    It  is  used  against  insects  and 
fungi. 

Lime  (unslaked) 25-40  pounds. 

Salt 15 

Sulphur 20 

Water 60       gallons. 

To  mix  the  above,  take  10  pounds  of  lime,  20  pounds  of  sul- 
phur, and  20  gallons  of  water.  Boil  until  the  sulphur  is  thor- 
oughly dissolved.  Take  the  remainder —  15  pounds  of  lime  and 
15  pounds  of  salt  —  slake  and  add  enough  of  water  to  make  the 
whole  60  gallons.  Strain,  and  spray  on  the  trees  when  milk- 
warm,  or  somewhat  warmer.  This  can  be  applied  when  the 
foliage  is  off  the  tree,  and  will  have  no  injurious  effects  on  the 
fruit-buds  or  on  the  tree  itself. 

LIME  SULPHIDE  ;  SULPHIDE  OF  LIME  ;  CAS.  —  This  sub- 
stance is  made  by  boiling  together  sulphur  and  quicklime,  using 
equal  parts  of  each,  until  the  liquid  assumes  a  reddish  yellow 
color.  Even  twice  the  amount  of  sulphur  may  be  used  with 
the  above  quantity  of  lime,  and  an  excellent  article  will  still  be 
produced.  Lime  sulphide  is  of  a  white  color,  the  compound 
being  CaS.  As  the  boiling  is  continued,  a  yellow  color  appears, 
caused  by  the  formation  of  the  bisulphide  of  lime,  CaS2.  Upon 
prolonged  boiling  the  yellow  is  replaced  by  an  orange-red,  which 
is  the  color  of  a  third  compound,  the  pentasulphide  of  lime, 
CaS5.  This  is  particularly  rich  in  sulphur.  The  most  popu- 
lar method  of  using  lime  sulphide  is  described  under  GRISON 
LIQUID,  which  see.  The  compound  is  not  a  very  energetic 
fungicide,  but  is  valuable  in  treating  surface  mildews,  such  as 
the  oidium  of  the  grape.  It  is  also  of  value  in  controlling 
mildew  upon  plants  grown  under  glass,  such  as  the  peach,  cu- 
cumber, rose,  etc.  With  few  exceptions,  however,  the  copper 
compounds  are  to  be  preferred. 

LINSEED  OIL  EMULSION.  —  This  remedy  has  been  recom- 
mended by  S.  T.  Maynard  for  the  destruction  of  the  San  Jose 
scale  insect,  it  having  proved  to  be  very  efficient  in  controlling 
various  scale  insects  found  upon  cacti,  English  ivy,  rose,  apple, 
pear,  ash,  thorn,  and  willow. 

Hard  soap I  pound. 

Boiling  water,  enough  to  dissolve  the  soap. 
Linseed  oil 1  gallon. 


Materials  and  Formulas.  159 

Churn  thoroughly  until  a  pasty  emulsion  is  formed.  Dilute 
with  from  12  to  24  gallons  of  water.  The  remedy  has  not  yet 
been  thoroughly  tested. 

LIVER  OF  SULPHUR.     See  POTASSIUM  SULPHIDE. 

LONDON  PURPLE.     See  under  ARSENITE  OF  LIME. 

LYE.  —  The  success  following  the  use  of  soaps  for  destroying 
insects  has  lead  to  treatments  of  lye  for  the  same  purpose.  It 
may  be  used  as  follows : 

Concentrated  lye 1  pound. 

Water 3  gallons. 

One  and  one-fourth  pounds  of  potash  may  be  used  in  place 
of  the  lye.  These  solutions  are  very  caustic,  and  should  only 
be  used  upon  dormant  wood.  They  are  especially  useful  in 
destroying  scale  insects,  but  soft-bodied  insects  may  also  be 
exterminated  by  using : 

Concentrated  lye 1  pound. 

Water 40  gallons. 

It  is  well  to  wash  this  solution  from  delicate  foliage  in  the 
course  of  half  an  hour,  to  prevent  any  injury  which  might 
follow  if  the  insecticide  were  allowed  to  remain. 

LYE  AND  SULPHUR  WASH.  — 

Concentrated  lye 1  pound. 

(Potash  14  pounds.) 

Sulphur \\  pounds. 

Water 3  gallons. 

This  is  recommended  for  the  destruction  of  scale  insects,  but 
should  be  used  only  upon  dormant  wood. 
LYE  AND  WHALE-OIL  SOAP  WASH. — 

(a)  Concentrated  lye 1  pound. 

Water 1  gallon. 

Sulphur Is  pounds. 

Boil  until  all  the  ingredients  are  dissolved. 

(6)  Whale-oil  soap 14  pounds. 

Water 54  gallons. 


160  The  Spraying  of  Plants. 

When  the  soap  is  dissolved,  unite  solutions  (a)  and  (6),  and 
boil  for  a  short  time.  The  remedy  is  particularly  valuable  in 
treating  scale  insects  just  as  they  hatch  in  spring.  It  is  more 
effective  if  used  warm,  at  a  temperature  of  130°  F.,  taking  care 
to  reach  as  many  insects  as  possible. 

MERCURIC  CHLORIDE;  CORROSIVE  SUBLIMATE;  HoCL2. — 
It  is  made  by  subliming  a  mixture  of  mercuric  sulphate  and 
common  salt,  the  resulting  product  being  one  of  the  deadliest 
poisons.  Recommendations  for  its  use  as  an  insecticide  are 
occasionally  advanced,  but  the  poison  has  such  a  caustic  action 
upon  foliage,  that  it  cannot  be  used  with  safety. 

It  possesses  some  value  as  a  fungicide,  however,  especially  in 
preventing  scab  upon  potatoes.  For  this  purpose  use  : 

Corrosive  sublimate 2  ounces. 

Water 16  gallons. 

Scabby  seed  potatoes  should  be  soaked  in  this  solution  for 
about  an  hour  and  a  half  before  planting. 
MERCURIC  CHLORIDE  WASH.  — 

Corrosive  sublimate 1  ounce. 

Soft  soap 10  gallons. 

Alcohol  or  wood  spirit 1  pint. 

Water,  sufficient  to  make  a  stiff  paint. 

The  corrosive  sublimate  should  first  be  dissolved  in  the  alco- 
hol, and  this  solution  then  added  to  the  soap.  The  wash  is 
used  upon  the  bases  of  apple  trees  to  prevent  the  entrance  of 
borers,  and  for  this  purpose  it  has  been  highly  recommended. 

MIXTURE  No.  5  (of  the  U.  S.  Department  of  Agriculture). — 

Ammoniated  copper  sulphate 1  part. 

Ammonium  carbonate 1     " 

Twelve  ounces  of  the  mixture  should  be  dissolved  in  22 
gallons  of  water,  when  it  is  ready  for  immediate  use.  A  more 
concentrated  solution,  consisting  of  1  pound  to  25  gallons  of 
water,  has  also  been  recommended.  The  fungicide  has  not 
been  generally  adopted,  as  it  frequently  causes  injury  to  foliage. 
Before  being  dissolved,  the  mixture  should  be  kept  in  air-tight 
receptacles,  or  its  composition  will  change. 

MODIFIED  EAU  CELESTE.  —  This  well-known  fungicide  is  one 
of  the  best  now  in  use.  In  composition  it  is  practically  the 


Materials  and  Formulas.  161 

same  as  the  ammoniacal  solution  of  copper  carbonate,  since  this 
compound  is  first  formed,  and  is  then  dissolved  by  ammonia. 
A  solution  of  sodium  sulphate  is  also  present,  but  this  is  scarcely 
objectionable.  The  freshly  precipitated  carbonate  of  copper  is 
much  more  easily  dissolved  by  ammonia  than  the  dry  article  is, 
and  in  this  respect  the  preparation  is  superior  to  the  common 
ammoniacal  solution.  But  there  is  also  present  a  certain  amount 
of  the  sulphate  of  soda,  yet,  if  properly  diluted,  no  injury  should 
result  from  this  source.  Modified  eau  celeste  is  readily  prepared 
as  follows : 

Copper  sulphate 2  pounds. 

Sal-  soda 2  i      " 

Dissolve  these  separately  with  a  small  quantity  of  water  and 
slowly  unite  them.  When  chemical  action  has  stopped  add 

Ammonia,  26°  Beaume 1  quart. 

Or  ammonia,  22°  Beaume 3  quarts. 

This  concentrated  solution  should  be  diluted  before  an  appli- 
cation is  made,  with  from  50  to  100  gallons  of  water,  the  last 
being  probably  none  too  much.  The  fungicide  is  cheap  and  effect- 
ive. The  price  of  sal-soda  varies  from  \\  to  5  cents  per  pound. 

MOLASSES.     See  SUGAR. 

OIL. — None  of  the  oils  is  used  in  a  pure  form,  with  the  ex- 
ception of  kerosene;  a  few  others  are  occasionally  applied  in 
connection  with  some  other  substance. 

OIL  AND  ALKALI  WASH. — 

1.  Whale-oil U  gallons. 

Sal-soda 25  pounds. 

Water 25  gallons. 

The  sal-soda  is  first  dissolved  in  the  boiling  water,  after 
which  the  oil  is  added.  Apply  when  cooled  to  130°.  Use 
during  winter  for  scale  insects. 

2.  Concentrated  lye  (American,  80  per  cent) ...  1  pound. 

Potash i       " 

Water 6  gallons. 

In  place  of  the  lye,  one  can  use  ±  pound  of  Greenbank  pow- 
dered caustic  soda,  of  98  per  cent ;  or  1  pound  of  solid  caustic 

M 


162  The  Spraying  of  Plants. 

soda,  of  76  per  cent ;  or  1^  pounds  of  solid  caustic  soda,  of  63 
per  cent.  This  is  used  in  the  same  way  and  for  the  same  pur- 
pose as  No.  1. 

OREGON  WASH.  —  The  Oregon  wash  is  practically  the  same 
as  the  California  lime,  salt,  and  sulphur  wash,  with  the  excep- 
tion that  sulphate  of  copper  is  substituted  for  salt.  The  for- 
mula, as  given  by  Henry  E.  Dosch,  of  the  Oregon  State 
Board  of  Horticulture,  is  as  follows : 

"Place  100  pounds  of  sulphur  and  80  pounds  of  lime  in  a 
boiler  with  100  gallons  of  water,  and  boil  slowly  until  the 
sulphur  is  dissolved.  Dissolve  8  pounds  of  sulphate  of  copper 
in  hot  water,  add  to  20  pounds  of  slaked  lime,  and  mix  the 
whole  together.  When  ready  to  spray,  take  1  pound  of  the 
mixture  and  2£  gallons  of  hot  water,  for  winter  use,  applying 
lukewarm ;  1  pound  of  the  mixture  to  8  or  10  gallons  of  water 
for  summer  spray.  The  water  in  the  mixture  will  boil  away, 
leaving  a  solid  mass,  which,  however,  dissolves  readily  when 
hot  water  is  added  for  spraying." 

PARAFFINE.     See  KEROSENE. 

PARIS  GREEN.     See  page  121. 

PATENT  INSECTICIDES.  —  The  Division  of  Entomology  of  the 
United  States  Department  of  Agriculture  made  an  exhibit  at 
the  Columbian  Exposition,  in  1893,  of  forty-two  different 
patented  insecticides;  and  many  more  exist.  Some  possess 
value,  while  others  are  positively  unsafe  to  handle.  As  a  rule, 
it  is  better  and  cheaper  for  each  grower  to  prepare  the  insecti- 
cides and  also  the  fungicides  which  are  to  be  applied,  since  then 
there  can  be  no  doubt  as  to  their  composition. 

PERSIAN  INSECT  POWDER.     See  PYRETHRUM. 

PRECIPITATED  CARBONATE  OF  COPPER.  See  COPPER  CAR- 
BONATE. 

PODECHARD'S  POWDER.  — 

Copper  sulphate 45  pounds. 

Water,  enough  to  dissolve. 

Lime,  air-slaked 225      " 

Ashes 30      " 

Flowers  of  sulphur 20      " 

The  copper  sulphate  solution  should  be  poured  upon  the  lime, 
which  in  turn  must  be  surrounded  by  the  ashes  to  keep  the 


Materials  and  Formulas.  163 

liquid  within  bounds.  After  standing  twenty-four  hours  the 
sulphur  should  be  added,  and  then  all  the  ingredients  thoroughly 
mixed  together.  The  mixture,  when  dry,  should  be  passed 
through  a  sieve  having  eight  meshes  to  the  inch,  when  it  is 
ready  to  apply.  It  has  been  recommended  for  various  fungous 
diseases,  but  is  not  much  used. 

POTASH;  POTASSIUM.  —  Various  compounds  of  potash  have 
been  recommended  for  the  destruction  of  insects,  but  they  are 
not  always  effective,  whether  applied  at  the  root  or  on  the 
foliage. 

Kainit 1  ounce. 

Water 1  pint. 

Other  forms  may  be  used  in  the  same  manner,  but  foliage  is 
frequently  injured. 
POTASH  SOAP. — 

Concentrated  lye 1  pound. 

Cotton-seed  oil 3  pints. 

Soft  water 3  gallons. 

Boil  the  lye  in  water  until  dissolved,  then  add  the  oil  and 
boil  for  two  hours,  replacing  evaporated  water  with  hot  water 
from  time  to  time.  Use  1  pound  of  this  soap  to  8  or  10  gallons 
of  water  on  lice-infested  plants  or  trees,  and  wash  the  trunks 
and  branches  with  a  stiff  brush. 

POTASSIUM  SULPHIDE;  SULPHURET  OF  POTASSIUM;  LIVER 
OF  SULPHUR;  K2S.  —  This  substance  is  used  when  dissolved 
in  water  at  the  rate  of  £  to  1  ounce  in  1  gallon  of  water.  The 
solution  soon  loses  its  strength,  so  should  be  made  only  just 
before  using.  It  possesses  considerable  value  in  the  treatment 
of  certain  fungous  diseases,  as  gooseberry  mildew,  but  is  not  so 
energetic  as  the  copper  compounds.  Cost,  fifteen  to  twenty-five 
cents  per  pound. 

PYRETHRUM;  BUHACH;  DALMATIAN  INSECT  POWDER  ;  PER- 
SIAN INSECT  POWDER.  —  This  powder  is  obtained  from  plants 
of  the  genus  Pyrethrum.  It  owes  its  value  to  the  presence  of 
an  oil  which  is  exceedingly  poisonous  to  most  insects,  but  appar- 
ently harmless  to  the  higher  animals.  The  oil  acts  upon  the 
insect  only  when  in  contact  with  it,  in  the  same  manner  as 


164  The  Spraying  of  Plants. 

kerosene  and  similar  insecticides.  The  oil  is  particularly  abun- 
dant in  the  flower-heads  just  before  they  open,  and  the  plant  is 
best  cut  at  this  time.  The  stems  also  are  used,  and  they  may 
form  about  one-third  of  the  mass  to  be  ground  into  powder. 
The  oil  is  very  volatile,  so  the  dried  plants  should  not  be  exposed 
to  the  rays  of  the  sun,  to  a  high  temperature,  nor  to  moisture. 
After  being  dried,  they  should  be  placed  in  a  receptacle  which 
can  be  tightly  closed;  and  it  is  imperative  that  the  powder  be  so 
treated,  else  it  will  quickly  lose  its  strength. 

There  are  two  species  of  Pyrethrum  which  furnish  the  bulk 
of  the  commercial  articles.  P.  roseum  is  the  plant  that  is 
native  to  the  province  of  Transcaucasia,  and  from  it  is  obtained 
the  form  sold  as  Persian  insect  powder.  P.  cineraricefolium, 
however,  is  native  to  Dalmatia,  and  Dalmatian  insect  powder 
is  the  product  derived  from  this  plant.  Buhach  is  obtained 
from  a  cultivated  form  of  the  same  species.  This  plant  is  the 
one  mostly  grown  in  California,  and  for  this  reason  Buhach  is 
the  most  reliable  powder  to  use.  The  insecticidal  value  of  the 
plant  does  not  appear  to  diminish  under  cultivation,  and,  as 
Buhach  is  made  in  this  country,  it  is  more  apt  to  be  fresh. 
Both  species  are  cultivated  as  ornamental  plants,  and  it  is  prob- 
able that  they  have  equally  valuable  insecticidal  properties. 

Pyrethrum  can  be  used  in  a  great  variety  of  ways,  of  which 
the  following  are  the  most  important : 1 

"1.    In  solution.  — One  ounce  to  3  gallons  of  water. 

"2.  Dry,  without  dilution. — In  this  form  it  is  excellent  for 
thrips  and  lice  on  roses  and  other  bushes.  Apply  when  the 
bush  is  wet.  Useful  for  aphis  on  house  plants. 

"  3.  Dry,  with  dilution.  —  Diluted  with  flour  or  any  light  and 
fine  powder.  The  poison  may  be  used  in  the  proportion  of  1 
part  to  from  6  to  30  of  the  diluent. 

"  4.  In  fumigation.  —  It  may  be  scattered  directly  upon  coals, 
or  made  into  small  balls  by  wetting  and  moulding  with  the 
hands,  and  then  set  upon  coals.  This  is  a  desirable  way  of 
dealing  with  mosquitoes  and  flies. 

"  5.  In  alcohol.  —  (1)  Put  1  part  of  pyre  thrum  (buhach)  and 
4  parts  alcohol,  by  weight,  in  any  tight  vessel.  Shake  occa- 
sionally, and  after  eight  days  filter.  Apply  with  an  atomizer. 
Excellent  for  greenhouse  pests.  For  some  plants  it  needs  to  be 

i  Bailey,  "  Horticulturist's  Rule-Book,"  third  edition,  1895, 10, 11. 


Materials  and  Formulas.  165 

diluted  a  little.  (2)  Dissolve  about  4  ounces  of  powder  in  1 
gill  of  alcohol,  and  add  12  gallons  of  water. 

"  6.  Decoction.  —  Whole  flower-heads  are  treated  to  boiling 
water,  and  the  liquid  is  covered  to  prevent  evaporation.  Boiling 
the  liquid  destroys  its  value. 

"  7.  Water  extract.  —  Pour  2  quarts  hot  water  through  about 
a  half-pound  of  pyrethrurn,  held  in  a  coarse  bag,  and  then  add 
cold  water  enough  to  make  2  gallons,  and  it  is  well  to  stir  in 
the  powder  itself.  For  aphis  and  cabbage  worms.  It  will  keep 
but  a  few  days.  Or  the  extract  can  be  made  as  follows :  Make 
a  paste  of  2  tablespoon fuls  of  pyrethrum  by  adding  water. 
Stir  this  into  2  gallons  of  water,  and  apply  writh  a  fine  nozzle. 
This  is  recommended  for  the  rose-chafer. 

"8.  Pyrethro-kerosene  emulsion. — See  under  KEROSENE-PY- 
RETHRUM  EMULSION." 

The  cost  of  pyrethrum  varies  from  twenty  to  nearly  seventy- 
five  cents  per  pound. 

QUASSIA.  —  The  wood  of  Picrcena  (or  Picrasma)  excelsa  con- 
tains a  principle  which  is  fatal  to  many  insects  when  brought  in 
contact  with  them.  The  wood  has  an  extremely  bitter  taste, 
and  for  this  reason  it  has  been  supposed  that  seeds  placed  in 
water  in  which  the  wood  had  been  soaked  would  be  protected 
from  birds  and  vermin.  Its  value  for  this  purpose  is,  however, 
doubtful.  Quassia  wood  is  generally  sold  after  having  been 
cut  into  "  chips,"  and  it  is  commonly  used  as  follows : 

Quassia  chips 1  pound. 

Water 8  gallons. 

Boil  until  reduced  to  6  gallons. 

Another  formula  has  been  recommended  which  is  probably 
more  effective  than  the  preceding : 

Quassia  chips \  pound. 

Water 1  gallon. 

The  chips  are  boiled  in  the  water  for  about  fifteen  minutes ; 
the  liquid  should  then  be  strained,  and  to  the  solution  is  added 

Soft  soap \  pound. 

When  thoroughly  mixed,  the  liquid  is  ready  for  use.  This 
insecticide  is  not  very  energetic,  but  possesses  a  certain  value  in 


166  The  Spraying  of  Plants. 

destroying  plant  lice.     Quassia  chips  are  worth  from  six  to  ten 
cents  per  pound. 

QUASSIA  CHIPS  AND  WHALE-OIL  SOAP. — 

Quassia  chips 8  pounds. 

Whale-oil  soap 7      " 

Water 100  gallons. 

"  Soak  the  chips  twelve  hours  in  8  gallons  of  water,  or  if  hot 
water  is  used,  less  time  will  be  required.  Dissolve  the  soap 
by  boiling  in  sufficient  water  to  cover  it ;  strain  the  extracts 
from  the  quassia  and  add  the  two  ingredients  together.  Stir 
thoroughly  and  dilute  to  make  100  gallons. 

"This  solution  is  used  successfully  among  the  hop  growers 
for  exterminating  hop  lice  in  the  large  fields.  It  is  not  injurious 
to  foliage.  .  .  .  For  some  species  of  aphis  [upon  other  plants] 
a  stronger  solution  may  have  to  be  used,  and  in  such  cases  dilute 
only  to  80  gallons  instead  of  100."  * 

QUICKLIME.     See  LIME. 

RESIN  SOAP. — 

Resin 2  pounds. 

Caustic  soda 1  pound. 

Tallow 1     " 

Dissolve  the  caustic  soda  in  1^  gallons  of  water.  In  this, 
dissolve  the  resin  and  tallow  with  moderate  heat,  adding  water 
to  make  22  pints  of  brown,  thick  soap.  For  use  dilute  with 
44  gallons  of  water  and  apply  as  a  spray.  It  is  used  as  a  sum- 
mer wash  to  destroy  insects. 

RESIN  WASHES.  —  The  history  of  these  washes  has  been  dis- 
cussed on  page  85.  Their  action  is  of  two  kinds.  Some  insects 
are  killed  when  these  washes  come  in  contact  with  their  bodies, 
an  action  similar  to  that  of  the  kerosene  emulsions.  But  scale 
insects  are  often  so  well  protected  that  they  cannot  be  directly 
reached  by  the  applications.  The  action  of  the  resin  washes  is 
then  to  form  a  covering  over  the  insect  so  that  both  air  and 
moisture  will  be  excluded.  In  this  manner  the  pest  is  literally 
smothered  to  death.  These  washes  are  particularly  valuable  in 
destroying  scale  insects.  In  the  East,  where  such  insects  are  less 
troublesome,  kerosene  emulsion  is  more  commonly  recommended, 

*  Washington  State  Board  of  Sort.  3d  Biennial  Sept.  1893-94,  71. 


Materials  and  Formulas.  167 

and  it  may  be  that  the  insects  are  also  more  easily  treated  here. 
But  in  California  and  in  the  South,  the  resin  solutions  are  very 
highly  valued,  as  they  appear  to  be  more  efficient  than  those 
containing  kerosene. 

Applications  are  made  to  dormant  as  well  as  to  growing  trees. 
In  the  former  pase  stronger  mixtures  are  used  with  success,  but 
if  used  during  summer,  the  same  ones  might  cause  much  dam- 
age. When  selecting  from  the  formulas  given  below,  the  nature 
of  the  treatment  must  be  kept  in  mind,  to  avoid  injuring  the 
trees.  It  is  advisable  to  use  a  covered  iron  kettle  for  boiling  the 
ingredients  of  the  insecticides. 

Resin 20  pounds. 

Caustic  soda  (70  per  cent) 5      " 

Fish-oil ,  2£  pints. 

Water  to  make 100  gallons. 

The  first  three  ingredients  should  be  placed  in  a  large  kettle 
and  covered  with  four  or  five  inches  of  water.  Boil  for  one  or 
two  hours,  or  until  the  liquid  has  a  dark  brown  color  resembling 
coffee. 

The  use  of  a  98  per  cent  granulated  caustic  soda  shortens  the 
required  time  of  boiling.  In  case  this  is  used,  its  amount  may 
be  reduced  to  3  pounds,  and  3  pounds  of  fish-oil  should  also 
be  added.  Under  such  circumstances,  these  ingredients  may  be 
boiled  a  moment  with  but  15  gallons  of  water  and  a  stock  solu- 
tion thus  obtained,  which  may  be  diluted  at  will.  (The  total 
cost  is  about  five  and  one-third  cents  per  gallon.)  These  two 
formulas  are  very  extensively  employed  in  the  work  of  the  United 
States  Department  of  Agriculture. 

When  water  is  added  to  the  solutions,  it  should  be  poured  in 
slowly  and  thoroughly  mixed.  Dilute  as  required,  in  green- 
houses 1—3,  or  1-4.  For  use  in  summer. 

Resin 40  pounds. 

Caustic  soda  (98  per  cent) 10       " 

Potash 10      " 

Tallow "40      " 

Water  to  make 50  gallons. 

Dissolve  the  soda  and  the  potash  in  about  10  gallons  of  hot 
water.  The  resin  and  the  tallow  should  be  heated,  and  when 
dissolved  and  thoroughly  mixed,  pour  the  two  solutions  into  a 


168  The  Spraying  of  Plants. 

barrel  holding  50  gallons,  and  stir  well.  Allow  the  mixture  to 
stand  about  two  hours,  when  the  barrel  may  be  slowly  filled 
with  warm  water,  the  contents  being  continually  stirred  as  the 
water  is  added.  One  pint  of  the  preparation  may  be  used  in  a 
gallon  of  warm  water.  For  use  in  summer. 

Kesin 20  pounds. 

Caustic  soda 8       " 

Fish-oil 1  gallon. 

Water  to  make 100  gallons. 

The  caustic  soda  is  first  dissolved  in  about  16  gallons  of 
water,  after  which  half  of  the  solution  is  taken  out  and  the 
resin  added  to  that  remaining  in  the  kettle.  When  all  the 
resin  is  dissolved,  the  fish-oil  is  added  to  it,  and  the  whole 
thoroughly  stirred,  after  which  the  balance  of  the  caustic  soda 
solution  is  added  very  slowly  and  boiled  for  about  an  hour,  or 
until  it  will  readily  mix  with  water.  Use  an  iron  kettle.  For 
use  in  summer. 

Resin 17£  pounds. 

Soda  (60  per  cent) 7      " 

Fish-oil 3      " 

Petroleum 2       " 

Water 100  gallons. 

Boil  the  first  three  ingredients  together  for  four  hours  in  20 
gallons  of  water,  after  which  the  petroleum  should  be  poured  in, 
the  whole  being  well  stirred.  The  80  gallons  of  water  may  then 
be  added,  and  an  emulsion  made  by  active  agitation.  For  use 
in  summer. 

Resin 8  pounds. 

Caustic  soda 1  pound. 

Water  to  make 22  gallons. 

Dissolve  the  caustic  soda  in  about  1  gallon  of  water.  When 
dissolved  half  the  solution  is  taken  out,  and  the  resin  added  to 
the  remainder  and  boiled  until  dissolved,  after  which  the  bal- 
ance of  the  soda  solution  is  added  very  slowly.  The  mixture  is 
then  boiled  over  a  hot  fire,  being  stirred  almost  constantly  ;  and 
when  cooked  sufficiently  it  will  assimilate  with  cold  water  like 
milk,  which  it  much  resembles.  Dilute  as  above,  and  apply 
during  summer. 


Materials  and  Formulas.  169 

Simple  solution  of  resin : 

Resin 2  pounds. 

Crystallized  sal-soda 1  pound. 

Water 2  quarts. 

Boil  the  above  until  a  clear  brown  solution  is  obtained.  This 
is  an  excellent  method  of  obtaining  a  stock  solution  of  resin. 
It  is  as  valuable  as  any  soap  to  increase  adhesive  properties  of 
Bordeaux  mixture,  and  costs  much  less. 

Resin 30  pounds. 

Caustic  soda  (70  per  cent) 9       " 

Fish-oil 4£  pints. 

Water 100  gallons. 

Place  the  first  three  ingredients  in  an  iron  kettle  and  cover 
with  five  or  six  inches  of  water.  Boil  for  an  hour  or  two,  or 
until  the  liquid  has  a  dark  brown  color,  after  which  the  re- 
mainder of  the  water  may  be  slowly  added.  It  is  not  necessary 
that  all  should  be  immediately  used,  since  the  liquid  may  be 
diluted  as  well  later.  For  winter  use. 

RESIN  WASHES  AND  ARSENICALS.  —  Paris  green,  London 
purple,  and  even  arsenious  acid  will  mix  readily  with  resin 
compounds,  especially  those  which  consist  of  resin,  caustic  soda, 
and  water.  The  poison  may  then  be  used  at  the  same  rate  as 
in  clear  water.  Arsenious  acid  has  been  used  in  this  manner 
upon  orange  trees  at  the  rate  of  1  pound  to  300  gallons  of  the 
wash. 

SALT;  SODIUM  CHLORIDE;  NACL. —  Common  salt  has  very 
frequently  been  recommended  as  an  insecticide,  and  there  is 
no  doubt  that  it  is  capable  of  killing  many  insects.  But  its 
effective  use  requires  such  strong  solutions  that  the  remedy  is 
generally  worse  than  the  disease,  and  for  this  reason  it  is  rarely 
applied. 

SCHEELE'S  GREEN.     See  ARSENITE  OF  COPPER,  page  120. 

SCHWEINFURTH'S  GREEN.     See  Paris  Green,  page  121. 

SKAWINSKI'S  IRON  SULPHATE  AND  SULPHURIC  ACID  SOLU- 
TION. — 

Iron  sulphate 110  pounds. 

Sulphuric  acid  (53°) 1£  pints. 

Warm  water  , . .  ? . , 26  gallons. 


1TO  The  Spraying  of  Plants. 

The  acid  should  first  be  poured  upon  the  iron  crystals,  after 
which  the  water  may  be  added.  This  preparation  is  almost 
identical  with  one  already  described  under  IRON  SULPHATE, 
and  it  is  used  for  the  same  purpose.  It  has  shown  itself,  in 
the  hands  of  Skawinski  and  others,  to  be  a  very  efficient  remedy 
against  grape  anthracnose,  being  applied  exclusively  to  dormant 
wood. 

SKAWINSKI'S  POWDER. — 

Copper  sulphate,  powdered 22  pounds. 

Alluvial  earth,  or  soot 33       " 

Coal-dust 165      " 

Mix  thoroughly  and  apply  in  the  form  of  a  powder.  The 
preparation  has  been  successfully  applied  in  Europe  for  treat- 
ing grape  mildews,  but  is  at  present  little  used. 

SNUFF.  —  Fresh  snuff  is  as  valuable  as  other  forms  of  tobacco 
in  destroying  insects.  It  may  be  used  dry  or  as  a  decoction ; 
for  the  latter  use  see  Tobacco.  When  dry  it  is  very  service- 
able in  destroying  insects  where  more  energetic  measures  can- 
not be  taken,  as  in  dwelling-rooms  and  small  conservatories. 
The  powder  should  be  blown  upon  the  insects. 

SOAP.  —  Probably  all  soaps  are  of  value  as  insecticides,  and 
they  were  among  the  first  remedies  used.  They  kill  by  corning 
in  contact  with  the  insect,  destroying  it  directly,  as  does  kero- 
sene, and  probably  also  by  closing  the  breathing  pores,  and  so 
smothering  it.  Common  soap  may  be  used  at  the  rate  of 

Soap 1  pound. 

Water 5-8  gallons. 

The  proper  strength  of  the  preparation  varies  with  the  insect 
and  the  plant  to  which  it  is  applied.  For  plant  lice,  the 
weaker  solutions  are  sufficiently  strong,  but  for  mealy-bug  and 
similar  pests  the  more  concentrated  forms  are  desirable. 

SOAP  AND  ARSENITES. — 

Soap 4  pounds. 

Paris  green  or  London  purple 4  ounces. 

Lime 4       " 

Water 50  gallons. 

Dissolve  the  soap  in  1  to  2  gallons  of  hot  water,  then  add 
the  poison  and  the  lime.  Dilute  just  before  using.  This 


Materials  and  Formulas.  171 

preparation  combines  certain  properties  of  those  insecticides 
which  kill  by  contact,  and  those  which  are  first  eaten.  It 
possesses  value  for  all  insects,  but  only  soft-bodied  organisms 
are  overcome  by  the  soap.  Kerosene  emulsion  or  the  resin 
washes  are  commonly  to  be  preferred.  The  lime  is  added  to 
the  preparation  to  prevent  injury. 
SOAP  AND  FISH-OIL. — 

Potash  lye 1  pound. 

Fish-oil 3  pints. 

Soft  water 3  gallons. 

First  dissolve  the  lye  in  the  water  by  boiling,  then  add  the 
oil  and  boil  two  hours  longer.  Dilute  with  6  to  10  gallons  of 
water  to  every  pound  of  the  soap  which  is  formed.  The 
mixture  is  especially  valuable  for  destroying  soft-bodied 
insects. 

SOAP  AND  LIME  WASH. — 

(a)  Potash 5  pounds. 

Lard 5      " 

Boiling  water 5  gallons. 

(6)  Quicklime 1  peck. 

Boiling  water 5  gallons. 

When  (a)  and  (b)  have  been  thoroughly  acted  upon  by  the 
hot  water,  mix  the  two  liquids.  Dilute  before  using  by  adding 
2  gallons  of  boiling  water  to  each  gallon  of  the  mixture.  This 
preparation  has  been  recommended  for  borers,  but  it  is  of 
doubtful  value. 

SOAP  AND  SODA  WASH.  —  Add  a  strong  solution  of  common 
wash  soda  to  soft  soap  until  the  latter  thickens  to  a  thick  paint. 
The  mixture  is  of  value  in  destroying  bark  lice  and  similar 
insects. 

SOAP  AND  TOBACCO. — 

Soft  soap 8  pounds. 

Kain  water  (warm) 12  gallons. 

When  this  has  cooled,  add 

Strong  tobacco  decoction 1  gallon. 

This  has  been  recommended  for  the  destruction  of  soft-bodied 
insects,  and  undoubtedly  possesses  considerable  value. 


172  The  Spraying  of  Plants. 

SODA  AND  ALOES. — 

Washing  soda 2  pounds. 

Bitter  Barbadoes  aloes 1  ounce. 

Dissolve  the  above  in  hot  water,  and  when  cool  add 
Water 1  gallon. 

The  preparation  has  been  recommended  for  destroying  plant 
lice,  but  in  order  to  be  effective  the  plants  must  be  dipped  in 
the  mixture,  and  in  half  an  hour  syringed  off  with  clear  water. 

SODA  AND  RESIN  WASH. — 

Sal-soda 3  pounds. 

Hot  water 1  pint. 

Then  slowly  add 

Resin 4  pounds. 

Hot  water 2  pints. 

These  should  be  thoroughly  mixed,  and  before  using  should 
be  diluted  with  5  gallons  of  water. 
SODA  AND  WHALE-OIL  SOAP  WASH. — 

Sal-soda 25  pounds. 

Water 25  gallons. 

Boil  until  dissolved,  when  1|  gallons  of  whale  oil  should  be 
added.  It  is  applied  only  to  dormant  wood,  and  is  particularly 
useful  in  destroying  scale  insects.  Apply  at  a  temperature  of 
130°  F. 

SODIUM  ARSENATE.    See  ARSENATE  OF  SODA. 

SODA  WASH. — 

Washing  soda 2  pound. 

Water 2  gallons. 

The  liquid  is  ready  for  use  as  soon  as  the  soda  is  dissolved. 
It  has  a  caustic  action  upon  foliage,  so  should  be  used  only  upon 
dormant  wood.  It  is  said  to  be  of  value  against  borers  and 
scale  insects. 

SODIUM  HYPOSULPHITE;  NA2S2O3.  —  Solutions  of  the  hypo- 
sulphite of  soda  have  been  very  thoroughly  tested  in  respect  to 


Materials  and  Formulas.  173 

their  fungicidal  value,  but  the  results  have  not  been  so  satis- 
factory as  with  the  copper  compounds,  and  therefore  the  sub- 
stance is  but  little  used.  The  solution  may  be  prepared  by 
dissolving  1  pound  in  10  to  20  gallons  of  water,  although  there 
has  been  recommended  the  application  of  only  ^  ounce  in  10 
gallons.  The  latter,  however,  can  have  but  little  value.  The 
cost  of  this  substance  varies  from  six  to  fifteen  cents  per  pound. 
SODIUM  SULPHIDE  WASH. — 

(a)  Whale-oil  soap 30  pounds. 

Hot  water 60  gallons. 

(6)  American  concentrated  lye 3  pounds. 

Sulphur 6       " 

Boiling  water 2  gallons. 

Mixture  (6)  should  be  very  thoroughly  boiled  until  it  is  of  a 
dark  brown  color.  Chemically  it  is  the  sulphide  of  soda. 
Solutions  (a)  and  (ft)  should  then  be  mixed  and  boiled  half  an 
hour.  Before  using,  dilute  with  90  gallons  of  warm  water. 
The  remedy  is  of  value  for  scab  diseases  of  oranges. 

SUGAR.  —  Sugar  or  molasses  is  sometimes  added  to  copper 
compounds  to  assist  in  holding  a  certain  amount  of  the  copper 
in  solution.  It  has  long  been  known  that  when  concentrated 
solutions  of  sugar  and  copper  sulphate  are  mixed  there  is  pro- 
duced a  bluish-white  precipitate,  known  as  a  sulpho-saccharate 
of  copper.  It  is  soluble  in  water,  but  when  heated  the  com- 
pound is  broken  up,  and  the  copper  is  deposited  in  the  form  of 
a  red  powder,  the  protoxide  of  copper.  Recommendations  have 
been  made  to  add  molasses  at  the  rate  of  one-tenth  by  weight 
of  the  amount  of  copper  sulphate,  or  one-twentieth  its  weight 
of  sugar.  This  renders  a  portion  of  the  copper  in  the  Bordeaux 
mixture  immediately  soluble  ;  but  the  advantage  of  the  practice 
is  doubtful.  (See,  also,  page  50.)  The  presence  of  an  excess 
of  lime  in  the  Bordeaux  mixture  is  essential  to  the  proper 
manufacture  of  the  fungicide  with  these  materials. 

The  following  analysis  represents  approximately  the  com- 
position of  a  high-grade  molasses  : 

Sugar 50  per  cent. 

Other  organic  matter 20        " 

Ash 10        " 

Water 20       K 


174  The  Spraying  of  Plants. 

A  poor  quality  of  molasses  has  been  found  to  possess 

Sugar 44.00  per  cent. 

Glucose 1.47 

Ash 12.96 

Water 41.57 

SULPHATED  SULPHUR;  BLIGHT  POWDER. — 

Copper  sulphate,  anhydrous 3-8  pounds. 

Flowers  of  sulphur 90-100      " 

Mix  the  two  materials  and  apply  in  the  form  of  a  powder. 
The  mixture  was  formerly  supposed  to  possess  strong  f ungicidal 
properties,  but  it  is  now  little  used.  It  is  of  some  value  in 
treating  surface  mildews,  the  sulphur  probably  then  being  the 
active  principle. 

SULPHATE  OF  COPPER.     See  COPPER  SULPHATE. 

SULPHATE  OF  IRON.     See  IRON  SULPHATE. 

SULPHATINE  POWDER. — 

Anhydrous  copper  sulphate 2  pounds. 

Flowers  of  sulphur 20      " 

Air-slaked  lime 2      " 

The  ingredients  should  be  thoroughly  mixed,  when  they  may 
be  applied.  The  powder  is  supposed  to  be  of  value  as  a  fungi- 
cide, but  is  very  little  used. 

SULPHIDE  OF  LIME.     See  LIME  SULPHIDE. 

SULPHOSTEATITE    J         CuPRIC-STEATITE   ;        FOSTITE.  Sul- 

phosteatite  is  an  exceedingly  fine  blue  powder  consisting  of 
steatite  or  talc,  and  containing  also  from  2  to  10  per  cent  of 
copper  sulphate.  It  is  obtained  in  Europe,  and  was  first  intro- 
duced into  America  by  C.  H.  Joosten,  of  New  York,  in  1893 ; 
he  changed  the  name  to  "Fostite"  the  following  year.  The 
copper  contained  in  the  powder  is  largely  soluble,  and  in  con- 
sequence foliage  is  frequently  injured  by  the  use  of  the  fungi- 
cide. It  has  been  recommended  as  an  insecticide,  but  I  have 
failed  to  derive  any  benefits  from  its  use  for  this  purpose.  It 
is  not  so  valuable  as  other  copper  compounds,  yet  it  has  the 
desirable  quality  of  being  remarkably  adherent  to  foliage. 

SULPHUR;  FLOWERS  OF  SULPHUR;  S.  —  Sulphur  is  valuable 
both  as  an  insecticide  and  as  a  fungicide.  Its  use  for  the  first 


Materials  and  Formulas.  175 

purpose  is  practically  confined  to  greenhouses  and  conserva- 
tories, and  even  there  only  few  insects  are  affected  by  it.  It  is 
most  rapidly  applied  by  evaporating  in  a  sand  bath  over  an  oil 
stove,  but  extreme  care  must  be  given  that  it  does  not  take  fire, 
as  then  it  will  instantly  destroy  all  the  plants.  Red  spider  and 
related  insects  are  said  to  be  destroyed  by  the  fumes,  and  treat- 
ment should  be  made  as  soon  as  they  are  discovered,  or  even 
before.  Sulphur  may  also  be  evaporated  successfully  by  plac- 
ing it  upon  the  heating  pipes.  It  is  well  to  mix  it  with  an 
equal  amount  of  lime,  and  then  add  water  to  form  a  thick 
paint,  with  which  the  pipes  may  be  covered.  When  applied  in 
a  dry  form  directly  to  the  plants,  it  possesses  little  value  as  an 
insecticide.  A  moist  atmosphere  in  the  house  probably  renders 
the  fumes  more  effective. 

Sulphur  is  one  of  the  most  valuable  fungicides  for  the  treat- 
ment of  surface  mildews,  and  it  has  long  been  used  for  this 
purpose.  Previous  to  1880,  it  was  almost  the  only  fungicide 
used  in  Europe,  and  it  did  excellent  service  in  controlling  the 
European  mildews  which  attacked  the  vine  and  many  other 
plants,  whether  grown  under  glass  or  in  the  open.  Out  of 
doors  it  was  commonly  applied  in  a  dry  condition,  being  blown 
upon  the  plants  by  means  of  hand  bellows.  Under  glass  it  was 
used  in  three  ways :  in  the  form  of  powder,  when  mixed  with 
water,  and  when  evaporated  from  the  heating  surfaces.  The 
first  method  was  executed  in  the  same  manner  as  out-doors. 
When  mixed  with  water  both  the  sulphur  and  the  water  assist 
in  destroying  many  pests,  and  it  is  a  common  practice  to  make 
such  applications.  The  proportions  of  the  two  vary  greatly. 
It  has  been  recommended  to  use  1  ounce  of  sulphur  to  5  gallons 
of  water,  and  also  as  much  as  1  pound  to  1  gallon.  The  more 
dilute  mixtures  are  more  easily  applied,  and  if  the  work  is 
thoroughly  done,  are,  on  the  whole,  equally  valuable.  The  fumes 
of  sulphur  for  treating  mildews  are  obtained  as  described  above. 
When  the  powder  is  used  out  of  doors  the  value  of  the  remedy 
undoubtedly  rests  in  the  fact  that  the  sulphur  gradually  gives 
off  fumes  on  account  of  the  heat  of  the  sun,  and  the  mildews 
yield  for  the  same  reason  that  they  do  when  the  powder  is  evap- 
orated under  glass. 

One  of  the  most  valuable  preparations  of  sulphur  is  known  as 
Grison's  liquid,  which  see. 


176  The  Spraying  of  Plants. 

Sulphur  generally  sells  for  about  three  cents  a  pound  whole- 
sale, and  ten  cents  retail. 
SULPHUR  AND  LIME  POWDER. — 

Flowers  of  sulphur 1  part, 

Air-slaked  lime 1    " 

Mix  and  apply  in  form  of  a  powder.  The  mixture  is  of  value 
for  surface  mildews,  but  is  little  used  in  America.  The  Euro- 
pean grape  mildew  is  easily  controlled  by  it. 

SULPHUR  AND  SNUFF. — 

Flowers  of  sulphur 1  pound. 

Scotch  snuff 1      " 

Quicklime 1      " 

Soft  soap 1      " 

Lampblack i      " 

Water,  enough  to  make  a  thin  paint. 

This  formula  contains  an  excellent  variety  of  materials,  but 
other  and  simpler  ones  are  undoubtedly  equally  effective  in  the 
destruction  of  plant  lice,  for  which  the  above  is  particularly 
recommended.  It  should  be  used  only  upon  dormant  wood. 

SULPHUR  AND  WHALE-OIL  SOAP  WASH. — 

Sulphur $  pound. 

Boiling  water £  gallon. 

Boil  the  sulphur  for  fifteen  minutes.     To  this  add 

Whale-oil  soap 1  pound, 

and  boil  for  five  minutes.  Allow  the  mixture  to  stand  a  week, 
and  before  using,  dissolve  1  pound  in  a  gallon  of  hot  water, 
making  the  application  when  the  temperature  has  fallen  to 
130°.  It  is  supposed  to  be  a  repellent  of  various  burrowing 
larvae,  as  the  currant  borer,  and  others. 

SULPHURET   OF   POTASSIUM.      See  POTASSIUM    SULPHIDE. 

SULPHURIC  ACID.     See  IRON  SULPHATE. 

TOBACCO  ;  NICOTIANA  TABACUM.  —  The  active  principle 
of  tobacco  is  nicotine,  and  this  compound  gives  the  plant  its 
value  as  an  insecticide.  It  kills  by  coming  in  contact  with  the 
insects,  and  so  long  as  this  occurs,  the  method  of  its  application 
is  of  minor  importance.  It  is  most  commonly  used  for  the 


Materials  and  Formulas.  177 

destruction  of  plant  lice,  although  other  soft-bodied  insects 
may  also  be  overcome  by  the  applications.  The  mid-veins, 
or  "stems,"  are  the  parts  sold  for  insecticidal  purposes.  The 
simplest  method  of  using  them  in  greenhouses  is  to  strew  them 
under  the  benches,  making  the  layer  two  to  four  inches  thick, 
and  renewing  the  stems  eveiy  five  or  six  weeks.  Tender  plants 
may  easily  be  injured  in  this  manner.  Another  common  prac- 
tice is  to  burn  the  stems  in  the  houses,  placing  them  in  a  sheet- 
iron  receptacle  having  the  form  of  an  enlarged  stove-pipe  placed 
upon  end,  and  having  a  perforated  bottom.  Legs  should  be 
attached  at  the  bottom  to  keep  the  fire  from  the  floor.  Paper 
or  shavings  may  be  used  for  starting  the  fire,  yet  the  stems 
themselves  should  never  come  to  a  blaze,  but  only  smolder,  so 
that  large  volumes  of  smoke  may  be  produced.  If  the  stems 
are  dampened,  the  operation  is  more  effective.  About  one- 
half  pound  of  the  stems  to  every  500  square  feet  of  glass  is  the 
quantity  generally  used.  On  account  of  the  disagreeable  smell 
left  in  the  house  this  remedy  cannot  always  be  employed.  In 
place  of  it  there  may  be  used  semi-fluid  extracts  of  tobacco 
which  are  now  upon  the  markets.  When  evaporated  these  are 
very  efficient  in  destroying  aphis,  and  only  a  slight  odor 
remains. 

A  decoction  of  tobacco  stems  is  commonly  employed.  It 
is  prepared  by  steeping  the  stems  in  an  amount  of  water 
sufficient  to  cover  them,  and  when  their  strength  has  been  well 
drawn  out,  the  liquid  is  diluted  so  that  it  has  the  color  of  fairly 
strong  tea.  It  is  then  sprayed  upon  the  plants,  care  being 
taken  that  the  insects  to  be  destroyed  are  reached  by  the  appli- 
cations. This  remedy  can  be  used  successfully  where  fumiga- 
tion is  not  advisable,  and  it  is  cheap  and  effective. 

Powdered  tobacco  or  snuff  may  also  be  used  'with  success. 
The  plants  to  be  treated  should  first  be  sprayed  with  clear 
water,  and  then  the  powder  may  be  blown  on  them.  The  water 
causes  it  to  adhere,  and  the  decoction  which  probably  results 
acts  energetically  in  destroying  the  pests. 

A  tobacco  decoction  is  frequently  employed  in  place  of  pure 
water  in  the  preparation  of  other  insecticides,  and  the  presence 
of  the  nicotine  renders  the  preparation  more  efficient.  With 
kerosene  emulsion,  however,  my  experience  has  been  such  that 
its  use  for  this  purpose  cannot  be  advised. 
N 


178  The  Spraying  of  Plants. 

VERATRUM  ALBUM  OR  V.  VIRIDE.     See  HELLEBORE. 

VERDET.     See  COPPER  ACETATE. 

VERDIGRIS.     See  COPPER  ACETATE. 

WASHES.  —  Many  washes  have  been  recommended  and  used 
for  preventing  injury  from  insects  and  fungi.  The  majority  of 
them  consist  largely  of  soapy  materials,  and  if  the  applications 
are  accompanied  by  a  rubbing  of  the  affected  parts  good  results 
will  follow,  especially  in  destroying  insects.  But  in  such  cases 
the  mechanical  action  is  perhaps  as  effective  as  the  material 
applied.  Clay  has  been  used  for  centuries  on  account  of  the 
benefits  which  are  supposed  to  have  followed  its  use  when 
mixed  with  water.  It  has  been  particularly  recommended  as 
an  agent  for  preventing  the  entrance  of  borers  into  trees,  and 
has  been  widely  used  for  this  purpose.  The  actual  value  of  the 
operation  is  probably  not  so  great  as  is  frequently  stated,  and 
much  profitless  labor  has  undoubtedly  been  performed  in  this 
direction. 

The  following  formula  is  inserted  here  not  because  it  possesses 
any  marked  value,  but  rather  for  the  purpose  of  illustrating  the 
varied  combinations  of  different  substances  which  have  been 
used  for  the  purpose  of  rendering  these  washes  more  efficient. 
This  one  has  been  well  recommended  for  preventing  the  en- 
trance of  borers  into  plum  and  peach  trees,  and  it  represents 
but  one  of  a  considerable  class  of  such  remedies : 

Carbolic  acid 1  quart. 

Soft  soap 3  gallons. 

Lime 4  pounds. 

Water 40  gallons. 

Clay,  enough  to  make  a  thick  wash. 

This  wash  is  very  adhesive,  and  on  this  account  has  attracted 
attention. 

WATER  ;  H2O.  —  Water  is  used  as  an  insecticide  in  three 
different  ways :  as  a  means  of  drowning  the  insect,  as  a  means 
of  forcibly  dislodging  and  indirectly  destroying  it,  and  as  a 
conveyance  for  killing  it  by  means  of  heat.  The  first  method 
is  employed  frequently  in  the  culture  of  the  cranberry,  the 
entire  bog  being  flooded  for  a  certain  period,  so  that  it  is  im- 
possible for  the  insects  to  escape.  European  vineyardists  make 
use  of  the  same  expedient  in  treating  their  vines  for  the  phyl- 


Materials  and  Formulas.  179 

loxera,  the  ground  remaining  covered  with  water  for  several 
weeks  during  the  winter,  when  the  plants  are  dormant.  It  is 
only  in  exceptional  cases  that  water  can  be  used  in  this  manner 
to  advantage. 

The  practice  of  dislodging  insects  by  means  of  a  stream  of 
water  forcibly  applied  is  confined  almost  wholly  to  florists. 
Plants  grown  under  glass  may  easily  be  kept  clean  in  this  man- 
ner, provided  the  water  may  be  used  freely ;  it  is  one  of  the 
best  remedies  for  mealy-bugs  and  similar  pests.  The  presence 
of  red  spider  upon  greenhouse  plants  is  principally  due  to  a  dry 
atmosphere,  and  no  good  gardener  need  be  troubled  by  this 
insect,  unless  some  very  good  reason  exists  why  the  plants 
should  not  be  syringed  or  sprayed.  A  moist  atmosphere  will 
also  check  the  growth  of  certain  fungi,  but  as  a  rule  such  condi- 
tions favor  their  development. 

The  value  of  hot  water  in  destroying  insect  life  has  long  been 
known.  If  an  insect  be  treated  with  water  having  a  tempera- 
ture of  125°-130°  F.,  it  will  succumb  almost  immediately,  and 
no  injury  to  the  plant  will  result.  Rose  chafers  will  yield 
readily  to  this  treatment,  but  great  difficulty  is  experienced 
in  maintaining  the  proper  temperature.  A  spray  is  cooled 
instantly,  and  when  a  solid  stream  is  used  the  operation  is 
slow  and  difficult.  For  this  reason  the  remedy  is  little  used. 

Cold  water,  that  having  a  temperature  little  above  freezing,  has 
been  recommended  against  soft-bodied  insects,  as  the  cabbage 
worm,  but  satisfactory  results  rarely  follow  such  applications. 

WHALE-OIL  SOAP.  —  The  value  of  this  soap  for  destroying 
insects  was  discovered  many  years  ago.  (See  page  14.)  The 
oil  from  which  the  soap  is  made  is  probably  the  active  prin- 
ciple. The  dissolved  soap  has  proved  itself  to  be  of  particu- 
lar value  in  destroying  scale  insects  when  used  at  the  rate  of 
1  pound  in  about  5  gallons  of  water.  Mealy-bugs  may  also  be 
destroyed  by  such  a  solution,  but  care  must  be  taken  to  see  that 
the  insects  are  wet  by  the  liquid.  Plant  lice  are  easily  killed 
with  much  weaker  solutions,  using  10  gallons  to  the  pound. 

Whale-oil  soap  may  also  be  highly  recommended  for  use  in 
preparing  emulsions  of  the  various  oils,  since  the  union  of  two 
good  insecticides  cannot  fail  to  make  the  mixture  more  eii'ect- 
ive  than  is  either  substance  alone.  The  soap  varies  in  price 
from  eight  to  twenty  cents  per  pound. 


180  The  Spraying  of  Plants. 

WHALE-OIL  SOAP  AND  SULPHIDE  OF  POTASH  WASH.  —  The 
following  formulas  for  a  summer  wash  have  been  recommended 
by  the  Horticultural  Commissioners  of  Sutter  County,  Cal. : 

"  Whale-oil  soap  (80  per  cent  strength) 20  pounds. 

Sulphur 3       " 

Caustic  soda  (98  per  cent  strength) 1  pound. 

Commercial  potash 1      " 

Water  to  make  100  gallons. 

"  Place  the  sulphur,  caustic  soda,  and  potash  together  in  about 
2  gallons  of  water  and  boil  for  at  least  an  hour,  or  until 
thoroughly  dissolved.  Dissolve  the  soap  in  the  water  by  boil- 
ing ;  mix  the  two  and  boil  them  for  a  short  time ;  use  at  130°  F. 
in  the  vessel. 

"  Professor  Hilgard  recommends,  in  bad  cases  of  scale  and  in 
fighting  red  spider,  an  addition  of  kerosene  in  the  form  of  an 
emulsion,  to  the  above  wash: 

"  Kerosene .• 1  gallon. 

Whale-oil  soap \  pound. 

Water £  gallon. 

"  Dissolve  the  soap  in  the  water  and  when  boiling  hot  add  the 
kerosene.  Churn  the  mixture  for  five  or  ten  minutes  with  a 
hand  spray-pump  until  it  forms  an  emulsion.  If  the  emulsion 
is  perfect  it  will  be  of  a  creamy  nature,  no  oil  appearing  on  the 
surface.  Add  this  to  the  100  gallons  of  spraying  material. 

"The  sulphide  of  potash  and  the  kerosene  emulsion  are  often 
made  up  in  large  quantities,  and  the  proper  amount  is  added  to 
the  whale-oil  soap  as  required.  Keep  this  wash  well  stirred 
when  using. 

"  It  is  very  important  that  the  whale-oil  soap  should  be  at 
least  80  per  cent  strength.  To  test  the  soap,  spread  five  or  ten 
ounces  of  it  on  a  tin  plate  counterpoised  on  a  pair  of  upright 
scales  reading  to  ounces,  and  then  dry  the  whole  by  setting  it 
on  top  of  a  pot  of  boiling  water.  The  loss  in  drying  will  indi- 
cate the  amount  of  water  in  the  soap.  Thus,  if  five  ounces 
were  taken  and  one  ounce  was  lost  in  drying,  the  soap  would  be 
of  80  per  cent  strength." 

WHITE  HELLEBORE.     See  HELLEBORE. 

YELLOW  PRUSSIATE  OF  POTASH.  See  FERROCYANIDE  OF 
POTASSIUM. 


CHAPTER  V. 


SPRAYING  DEVICES  AND  MACHINERY. 

THE  development  of  spraying  machinery  received  an  impetus 
about  the  same  time  that  the  injury  of  insects  and  fungi  began 
to  threaten  and  destroy  so  many  of  our  cultivated  plants.  For 
a  long  term  of  years  very  little  had  been 
done  towards  developing  apparatus  of  this 
character,  and  many  crude  contrivances 
were  used.  The  early  history  of  the  in- 
dustry reveals  many  appliances  which  are 
no  longer  in  use,  the  names  even  being 
nearly  as  obsolete  as  the  machines. 

I.  HISTORY  OF  SYRINGES  AND  PUMPS. 

The  simplest  device  for  making  liquid 
applications  to  the  stems  and  foliage  of 
plants  was  probably  a  whisk  of  heath, 
straw,  or  some  similar  material ;  the  stems 
were  tied  in  small  bundles,  the  part  above 
the  tie  serving  for  a  handle  (Fig.  1). 
Brooms  were  also  used  for  the  same  pur- 
pose. The  liquid  was  applied  by  first  dip- 
ping this  crude  brush  or  broom  into  it,  and 
then  throwing  upon  the  plant  what  ad- 
hered to  the  brush.  A  fairly  good  applica- 
tion can  be  made  in  this  manner,  although 
the  process  is  a  tedious  one.  This  device 
was,  nevertheless,  used  as  late  as  1882  in  France  for  the  purpose 
of  applying  mixtures  composed  of  the  sulphate  of  copper  and 
lime.  It  is  probable  that  the  density  of  this  preparation  pre- 
181 


FIG.  1.  —  Heath  whisk, 
the  first  device  used 
for  applying  Bor- 
deaux mixture. 


182 


The  Spraying  of  Plants. 


vented  it  from  being  applied  by  means  of  other  devices  then 
known.  Since  brooms  were  used  in  applying  liqiiids  and  semi- 
liquids  to  plants  even  less  than  twelve  years  ago,  it  is  not  im- 
possible that  in  certain  sections  the  practice  may  still  be  in 
vogue.  For  many  plants  it  is  surely  much  better  to  use  a  device 
of  this  character  than  it  is  to  make  no  application,  for  low- 
growing  plants  can  be  fairly  well  treated,  and  they  should  be 
benefited  nearly  as  much  as  if  more 
costly  machinery  were  used.  The 
character  of  many  crops  grown 
during  the  past  few  seasons  indi- 
cates that  plants  will  repay  treat- 
ment whatever  be  the  nature  of  the 
method  followed.  An  improved 
brush  is  shown  in  Fig.  2.  The 
liquid,  which  was  carried  in  a  tank 
on  the  back  of  the  operator,  entered 
the  hollow  handle  through  a  tube 
connected  with  the  bottom  of  the 
tank.  The  fluid  then  ran  along 
the  fibers  of  the  broom,  and  was 
thrown  from  the  extremities.  The 
flat  broom  was  attached  to  a  broad 
piece  of  oilcloth,  which  assisted  in 
making  a  uniform  application.  A 
stopcock  was  inserted  in  the  handle 
so  that  the  liquid  could  be  shut  off 
when  desired.  This  device  was 
used  in  France  for  applying  the 
Bordeaux  mixture. 

The  watering-can  is  one  of  the 
first  contrivances  made  for  apply- 
ing liquids  upon  plants.  Its  structure,  as  a  rule,  is  very  simple, 
being  composed  of  nothing  more  than  a  cylindrical  reser- 
voir capable  of  containing  one  or  more  gallons  of  liquid. 
This  device  is  still  in  very  common  use,  especially  among 
florists.  The  water  or  other  liquid  is  poured  out  through  a 
tube  which  projects  on  the  outside  of  the  reservoir,  and  which 
springs  from  the  bottom  or  from  near  the  bottom  of  the  can. 
These  tubes  or  sprouts  are  of  varying  lengths  and  shapes,  and 


FIG.  2.  —An  improved  brush  for 
distributing  Bordeaux  mix- 
ture. 


4 


Spraying  Devices  and  Machinery.  183 


are  often  jointed ;  the  cans  also  differ  much  from  each  other. 
The  water  may  be  broken  up  into  fine  drops  by  means  of  a 
perforated  disk,  or  rose,  which  covers  the  outer  opening  of  the 
spout,  the  size  of  the  drops  varying  with  the  size  of  holes  in  the 
rose.  Watering-cans  are  used  advantageously  only  on  very  low- 
growing  plants,  as  the  liquid  leaves  the  spout  by  the  force  of 
gravity,  and  not  by  pressure  applied  by  the  operator.  Very 
thorough  applications  can  be  made  by  means  of  these  cans,  but 
they  are  wasteful  of  materials. 

Small  hand  pumps,  commonly  called  syringes,  came  into  use 
at  an  early  day.  They  were  very  simple  in  construction, 
were  at  first  used  almost  entirely 
for  throwing  clear  water  upon 
cultivated  plants.  They  con- 
sisted practically  of  nothing  but 
a  tube  in  which  a  piston  and 
piston-rod  could  play.  The  water 
was  thrown  out  of  the  same  ori- 
fice through  which  it  entered. 
Such  a  contrivance  admitted  of 
considerable  variation,  and  sev- 
eral styles  have  been  described 
in  very  early  publications. 

A  more  complicated  form  of 
syringe  includes  those  which  are 
supplied  with  valves,  generally 
two  (Fig.  3).  In  such  syringes 
the  liquid  does  not  leave  the  cyl- 
inder through  the  same  orifice 
at  which  it  entered,  but  it  passes 
out  through  another.  These  orifices  are  each  supplied  with  a 
valve  which  allows  of  the  free  passage  of  water  in  the  desired 
direction,  but  prevents  its  return.  The  earlier  forms  of  these 
syringes  were  made  principally  by  the  English,  and  several  more 
or  less  modified  forms  have  been  described.  The  principal  ones 
appear  to  have  been  Read's,1  Macdougal's,2  Warner's,3  Johnston's 
portable  garden  engine,4  and  Siebe's  universal  garden  syringe.6 


G.  3.  —  Small  hand  syriuge  having 
eparate  inlet  and  outlet  orifices. 


1  "  Loud.  Ency.  of  Gard."  1STS,  546. 
*  Gard.  Jfag'.\o\.  vi.  305. 
»  Ibid.  Vol.  vili.  353, 


*  "Loud.  Ency.  of  Gard."  1878,  547. 
« Ibid.  loc.  Git. 


184  The  Spraying  of  Plants. 

Many  other  syringes  could  be  mentioned,  but  the  above  repre- 
sent the  principal  ones  in  use  in  England  as  well  as  in  other 
European  countries.  American  gardeners  also  used  them  ex- 
tensively, and  this  type  of  syringe  is  still  very  commonly  found, 
although  in  a  much  modified  form.  The  following  syringe  is  one 
of  the  most  popular  recently  used  (Fig.  4)  :  "  In  applying  Paris 
green  or  any  other  solutions  to  fruit  or  ornamental  trees,  Whit- 
man's fountain  pump  is  invaluable.  It  will  throw  a  stream 
thirty  feet  high,  sixty  feet  horizontally,  and  works  so  easily 
that  a  child  five  years  old  can  work  it.  It  can  also  be  used 
advantageously  in  watering  plants,  cleaning  carriages  and  win- 
dows, and  might  enable  one  to  prevent  much  destruction  in  case 
of  fire.  The  pump  now  retails  at  seven  and'  one-half  dollars." l 


FIG.  4.  — Whitman's  fountain  pump. 

Garden  engines  were  designed  to  throw  larger  amounts  of 
iiquid  than  could  be  well  done  with  hand  syringes,  and  they 
were  also  generally  arranged  so  that  a  considerable  amount  of 
liquid  could  be  transported  from  one  part  of  the  grounds  to 
another.  A  large  number  of  different  kinds  were  made,  but 
the  majority  of  them  consisted  of  a  force  pump  fastened  upon 
a  tank.  The  pumps,  tanks,  and  the  devices  for  transporting  the 
outfit,  differed  considerably.  All  were  designed  to  throw  clear 
water,  or  solutions  which  contained  no  coarse  particles.  The 
nozzles  used  were  also  designed  for  the  same  purpose,  and  were 
very  simple  in  construction.  Fig.  5  represents  one  of  the  early 
machines  used  in  America. 

The  spraying  implements  in  use  in  America  and  in  Europe 
were  until  recently  very  similar.  The  comparatively  small 
amount  of  work  which  had  been  done  in  fighting  insect  and 
fungous  enemies  previous  to  1880  could  be  fairly  well  accom- 

i  Cook,  Kept.  Mich.  Pom.  Soc.  1878,  236. 


Spraying  Devices  and  Machinery.  185 


plished  with  the  machinery  then  made,  and  the  demand  for 
more  efficient  apparatus  was  not  sufficient  to  stimulate  invent- 
ors to  introduce  new  devices.  But  increasing  necessities  soon 
created  a  demand  for  improved  machinery,  and  this  quickly 
brought  about  the  production  of  new  implements  which  were 
adapted  to  the  wants  of  the  horticulturist. 

It  is  interesting  to  note  that  for  about  a  century  the  needs  of 
American  and  European  growers  were  practically  the  same,  and 
that  the  apparatus  used  by  the  one  was  also  adopted  by  the 
other.  Then  suddenly  all  changed.  The  Europeans,  and  par- 
ticularly the  French,  branched  off  and  made  machinery  for 
which  there  was  at  first  no  demand  in  this  country,  and  for  which 
there  is  even  now  com- 
paratively little.  The 
Americans,  on  the  other 
hand,  manufactured  ma- 
chinery that  is  not  used 
to  any  great  extent  in 
Europe,  even  to  this  day. 
It  was  between  the  years 
1870  and  1880  that  the 
American  growers  be- 
gan searching  for  pumps 
which  were  better  suited 
to  their  purpose  ;  but  it 
was  not  until  1880  to 
1885  that  this  demand 
had  much  effect  upon 
manufacturers.  In 
France,  new  machinery  was  demanded  also  between  the  years 
1880  and  1885,  so  it  may  indeed  be  said  that  the  breaking  away 
from  old  methods  after  a  century  of  uniformity,  took  place 
simultaneously  in  France  and  in  America. 

The  appearance  of  the  potato  beetle  in  the  central  and  east- 
ern portions  of  the  United  States,  between  the  years  1860  and 
1875,  familiarized  farmers  with  the  use  of  Paris  green,  the  use 
of  this  poison  proving  to  be  the  easiest  and  most  effectual 
method  of  dealing  with  the  insect.  The  poison  was  applied 
both  in  the  form  of  powder,  and  suspended  in  water.  But  the 
latter  method  was  not  so  generally  adopted,  as  difficulty  was 


FIG.  5. — An  early  form  of  garden  engine. 


186  The  Spraying  of  Plants. 

experienced  in  making  the  application.  In  1874,  Frank  M. 
Gray,  of  Jefferson,  Cook  County,  111.,  sent  to  Professor  C.  V. 
Riley,  then  of  Missouri,  a  sprinkler  which  was  designed  to 
spray  two  rows  of  potatoes  at  once.1  It  consisted  of  a  tank 
holding  about  eight  gallons,  and  was  so  arranged  that  it  could 
be  strapped  to  the  back  of  the  operator.  Two  leads  of  hose 
were  attached  at  the  bottom  of  the  tank.  At  the  outer  extrem- 
ity of  each  hose  was  a  nozzle  or  sprinkler  which  broke  the 
liquid  up  into  fine  drops.  The  flow  was  due  to  the  force  of 
gravity,  and  could  be  shut  off  at  will  by  clamps  placed  upon 
the  hose.  This  is  the  first  case  which  has  come  to  my  knowl- 
edge of  the  principle  of  a  knapsack  sprayer  being  used  in/ 
combating  the  pests  of  cultivated  plants.  It  will  be  noticed, 
however,  that  no  pump  was  fastened  to  this  machine.  Several 
devices,  resembling  the  above  more  or  less,  have  since  been  con- 
structed, but  they  have  not  met  with  much  favor. 

W.  P.  Peck,  of  West  Grove,  Penn.,  made  another  machine 
for  applying  Paris  green  in  water.2  He  also  used  a  tank  strapped 
to  the  back,  but  atomized  the  liquid  by  means  of  a  crank  which 
operated  a  pair  of  bellows.  The  machine  was  also  provided 
with  an  automatic  agitator  which  prevented  the  poison  from 
settling. 

The  first  knapsack  pumps  used  in  America  were  imported 
from  France,  and  it  was  not  until  1890  that  Americans  began 
seriously  to  consider  their  manufacture.  In  France,  their  use 
is  also  very  recent,  since,  at  the  close  of  the  year  1885,  these 
machines  were  scarcely  known.  The  manufacture  of  two  forms 
had  just  begun,  their  structure  having  undoubtedly  been  sug- 
gested by  the  conditions  under  which  the  Bordeaux  mixture 
could  be  most  thoroughly  applied.  One  machine  was  made  by 
Gaillot,  of  Beaune  (Cote  d'Or).8  It  was  constructed  so  that 
air  was  forced,  by  means  of  an  exterior  pump,  into  the  liquid 
at  the  bottom  of  the  tank,  and  the  contents  were  kept  agitated 
by  the  rising  air.  The  other  form  was  manufactured  by  Kat- 
terbach,  also  of  Beaune ;  but,  as  it  appears  to  have  been  little 
used,  it  cannot  have  been  of  much  value.  Four  or  five  different 

i  Eiley,  "  Potato  Pests,"  1876,  63. 
» Ibid.  64. 

3  Eicaud,  Jour.  &Ag.  Prat.  1885,  Dec.  3,  795 ;  also  Gaillot,  Ibid.  1888,  May 
24,  733. 


Spraying  Devices  and  Machinery.  187 


machines  were  exhibited  at  a  fair  held  in  Montpellier,  France, 
during  February,  1886,  and  a  great  number  were  manufactured 
and  sold  within  the  next  few  years.  Hand  or  barrel  pumps 
were  rarely  used.  The  most  popular  knapsack  pumps  now 
made  in  France  are  the  Eclair,  the  Vigouroux,  the  Japy,  and 
the  Albrand.  The  first  (Fig.  6)  is  manufactured  by  Vermorel, 
Villefranche  (Rhone).  It  is  made  without  a  piston,  the  liquid 
being  propelled  by  means  of  a  circular  rubber  disk  B  which  is 
fastened  at  the  edges, 
but  moves  up  and 
down  in  the  center, 
thus  forcing  on  the 
liquid  contained  be- 
tween the  disk  and  the 
bottom  of  the  tank,  C. 
The  liquid  in  the  reser- 
voir, R,  flows  through 
the  valve,  L,  entering 
the  space  above  the 
disk.  When  the  latter 
is  forced  upward  by 
the  action  of  the  han- 
dle, K,  the  fluid  is 
forced  through  a  sec- 
ond valve,  V,  into  a 
second  receptacle, 
which  serves  as  an  air 
chamber,  D.  From 
here  it  passes  through 
the  orifice,  H,  and  is 
discharged  at  the  end 
of  a  hose  provided  for  the  purpose.  When  the  center  of  the 
disk  is  lowered,  more  fluid  is  drawn  in  from  the  reservoir,  and 
in  this  manner  the  pumping  is  performed. 

The  Yigouroux  pump  contains  an  air  chamber  and  piston 
pump  within  the  tank.  The  piston  is  moved  by  means  of  a  rod 
which  ascends  through  the  top  of  the  tank,  and,  after  turning 
sharply,  descends  on  the  outside  to  below  the  tank,  where  it  is 
attached  to  the  lever  which  serves  as  a  handle.  Another  form, 
one  which  is  provided  with  a  second  pump  for  filling  the  tank 


FIG.  6.  —The  "ficlair  "  knapsack  pump. 


188 


The  Spraying  of  Plants. 


without  removing  it  from  the  back,  is  also  made  by  the  same 
manufacturer. 

The  Japy  pump  (Fig.  7)  is  very  like  the  preceding,  but  the  pis- 
ton rod  is  worked  by  a  lever  situated  within  the  tank,  the  lever 
in  turn  being  moved  by  a  rod  extending  through  the  top  of  the 
reservoir.  Both  the  cylinder  and  the  air  chamber  project  below 
the  tank.  For  plans  of  an  improved  Japy  pump,  designed  by 
B.  T.  Galloway,  see  Journal  of  Mycology,  Vol.  vii.  No.  1,  39. 


I 


FIG.  7.  — The  "Japy"  knapsack  pump.     Fio.  8. — The  "Albrand"  knapsack  purap. 

The  Albrand  (Fig.  8),  manufactured  by  Valloton,  Lyons, 
France,  is  provided  with  an  air  pump  situated  on  one  side  of 
the  tank,  near  the  top.  Air  is  forced  into  the  reservoir,  the 
outlet  of  the  conducting  tube  being  near  the  bottom,  thus 
agitating  the  liquid.  The  pressure  of  the  air  within  the  tank 
forces  out  the  liquid. 

B.  T.  Galloway,  of  the  United  States  Department  of  Agricul- 
ture, was  the  first  in  this  country  to  publish  detailed  plans  for 
the  construction  of  knapsack  pumps.1  His  recommendations 
have  been  followed  more  or  less  closely  to  the  present  time,  but 

1  Journal  of  Mycology,  Vol.  vi.  1890,  Sept.  10,  pp.  26  and  51. 


Spraying  Devices  and  Machinery.  189 


several  minor  changes  have  been  made.  His  pump  (Fig.  9) 
consists  of  a  knapsack  tank  carried  on  the  back  of  the 
operator.  The  pump  proper  is  composed  of  a  tube  or  cylin- 
der which  projects  a  short  distance  above  the  top  of  the  tank, 
the  lower  end  being  near  the  bottom  of  the  reservoir.  The 
piston  is  moved  by  means  of  a  handle  which  extends  forward 
in  such  a  manner  that  it  can  be  worked  easily  by  the  person 
carrying  the  pump.  No  pressure  is  brought  to  bear  upon  the  air 
above  the  liquid,  but  all  necessary  force  is  applied  directly  to 
the  liquid  by  means  of  the 
working  parts  of  the  pump. 
The  Galloway  knapsack 
sprayer,  as  the  machine  is 
commonly  called,  was  first 
manufactured  by  two  firms 
in  Washington,  D.C.1  A  few 
other  manufacturers  almost 
immediately  began  the  con- 
struction of  this  class  of 
pumps,  but  on  account  of 
the  limited  demand,  they 
were  not  produced  in  nearly 
such  large  quantities  as  were 
the  various  hand  and  barrel 
pumps.  One  company2  put 
an  enormous  air  chamber 
above  the  tank  the  first  year 
it  sold  the  machine ;  as  this 
feature  was  advertised  only 
one  year  it  is  good  evidence  that  its  use  was  not  advisable. 
Later  styles  of  these  pumps  have  varied  in  the  shape  of  the 
tank,  and  many  desirable  features  have  been  added,  but  the  gen- 
eral plan  has  remained  unchanged.  They  are  almost  without 
exception  made  of  copper  and  brass,  and  consequently  withstand 
the  corroding  action  wrought  by  many  of  the  materials  applied. 
Rumsey  &  Co.  has  departed  from  the  Galloway  sprayer,  and 
now  manufactures  a  pump  in  which  air  is  forced  into  the  tank 
by  means  of  a  pump,  and  this  air  pressure  forces  out  the  liquid. 


FIG.  9. — The  "Galloway"  knapsack  pump. 


i  Albinson  &  Co.;  Leitch  &  Sons. 

*  Field  Force  Pump  Co.,  Lockport,  N.Y. 


190 


The  Spraying  of  Plants. 


Several  French  machines  are  built  in  this  manner,  one  of  the 
advantages  claimed  being  that  the  outfit  is  more  durable,  since 
the  materials  applied  do  not  come  in  contact  with  the  working 
parts  of  the  pump.  The  Galloway  type,  however,  is  at  present 

more  popular. 

The  use  of  Paris  green  to  de- 
stroy the  plum  curculio,  canker- 
worm,  and  the  codlin-moth,  soon 
created  a  demand  for  pumps  and 
nozzles  which  would  be  effective 
in  applying  sprays  to  well-grown 
trees.     Several  firms  soon  began 
to    supply    this    demand.     C.  J. 
Rumsey  &  Co.,  of  Seneca  Falls, 
N.Y.,  had  been  supplying  various 
garden  engines  as  early  as  1858, 
or  even  before.     In  1860  the  firm 
advertised    a   garden   engine    as 
an  instrument  for  "  the  throwing 
of   liquid  compounds, 
such  as  whale-oil,  soap- 
suds,   tobacco  -  water, 
etc.,  for  destroying  in- 
sects  on  trees,   roses, 
and  other  plants."  The 
outfit  consisted  of    a 
tank   resting   on    two 
wheels  in  front  and  on 
two    legs    behind  ;    it 
was  moved  about  as  a 

wheelbarrow   IS.      The 
pump     had     ail     enor- 

mous   air  chamber,  a 

part  which  has  fortunately  been  reduced  in  size  during  later 
years.  Various  small  hand  or  bucket  pumps  were  sold  soon 
after. 

On  Nov.  6,  1860,  Messrs.  W.  and  B.  Douglas,  of  Middletown, 
Conn.,  obtained  a  patent  on  a  garden  or  greenhouse  engine,  and 
in  the  same  year  the  same  company  patented  its  "  Aquarius,"  a 
bucket  pump  still  advertised. 


FIG.  10.  -The   "Florida"  barrel  pump,  the  first 
form  especially  designed  for  spraying  purposes. 


Spraying  Devices  and  Machinery.  191 


It  was  not  until  the  year  1880  that  the  pump  manufacturers 
of  this  country  fully  realized  the  necessity  of  taking  steps 
towards  supplying  the  growing  demand  for  pumps  especially 
designed  for  spraying  purposes,  and  the  next  five  years  showed 
that  many  were  giving  the  matter  serious  attention.  Xew  firms 
were  organized  with  the  special  object  of  manufacturing  and 
selling  pumps  and  other  materials  which  were  in  demand  by 
those  who  sprayed. 

In  1880  Rumsey  &  Co.  offered  for  sale  the  "  Florida  "  pump 
(Fig.  10),  which  seems  to  have  been  the  first  barrel  pump 
designed  especially  to  meet  the  re- 
quirements of  a  good  sprayer.  The 
firm  writes  me  that  "  its  introduc- 
tion was  followed  by  a  demand  we 
were  unable  to  supply."  This  state- 
ment is  emphasized  by  the  fact  that 
in  1882  the  well-known  firm,  the 
Field  Force  Pump  Co.,  of  Lockport, 
X.Y.,  was  founded,  to  supply  the 
demand  of  local  fruit  growers  for 
a  pump  which  would  be  satisfac- 
tory as  a  sprayer.  The  leading 
entomologists  of  the  country  were 
urging  the  farmers  to  spray,  and 
these  in  turn  made  demands  upon 
the  manufacturers ;  and  thus  the 
industry  arose.  In  1882  the  latter 
company  received  a  patent  upon  its 

combined  cistern  and  force  pump     FlG  n.  _  combined  cistern  and 
(Fig.    11).     This   pump   was   pro-  force  pump, 

vided  with  a  three-inch  cylinder, 

but  a  larger  size  had  one  that  was  three  and  one-half  inches  in 
diameter.  A  later  form  was  made  with  a  two  and  one-half 
inch  cylinder. 

In  1889  another  firm,  the  Nixon  Nozzle  &  Machine  Co., 
came  into  prominence.  At  this  time  it  advertised  two  garden 
engines,  the  "Little  Giant"  and  a  "Barrel  Machine";  the 
"  Little  Climax  "  pump  was  also  catalogued.  These  machines 
were  all  very  powerful,  and  were  made  particularly  to  supply 
the  growing  demand  for  spray  pumps. 


192 


The  Spraying  of  Plants. 


Morrill  &  Morley,  Benton  Harbor,  Mich.,  in  1894  introduced  a 
pump  shown  in  Fig.  12.  This  style  is  a  radical  departure  from 
older  forms.  The  cylinder  is  placed  at  the  bottom  of  the  pump, 
directly  in  the  liquid.  No  stuffing-box  is  used,  and  as  the  pis- 
ton and  cylinder  are  surrounded  by  the  fluid,  no  priming  is 

necessary.  These  pumps  are  sim- 
ple, powerful,  and  durable,  and 
many  are  now  in  use. 

In  recent  years  many  of  the 
leading  pump  manufacturers  have 
added  spray  pumps  to  their  cata- 
logues, and  other  firms  have  been 
established  which  make  a  specialty 
of  this  class.  As  so  many  differ- 
ent men  have  been  engaged  in 
the  work,  it  is  not  strange  that  a 
great  variety  of  pumps  should 
have  been  made.  Some  of  them 
are  excellent,  but  others  do  not 
answer  all  requirements  so  well  as 
might  be  desired.  One  form  that 
has  been  little  used  and  which  yet 
has  some  very  promising  features 
is  that  made  by  the  Bean-Cham- 
berlin  Manufacturing  Co.,  of  Hud- 
son, Mich.  The  firm  offers  a 
number  of  pneumatic  pumps  which 
differ  radically  from  the  pumps 
sold  by  other  dealers.  Instead  of 
using  directly  the  force  obtained 
by  the  moving  piston,  this  force  is 
directed  toward  compressing  air 
in  a  reservoir.  Fig.  13  illustrates  the  general  plan  upon  which 
these  pumps  are  built. 

The  pump  proper,  B,  is  situated  at  the  right  of  the  large  tank 
or  reservoir.  It  is  used  for  forcing  liquids  into  the  reservoir,  C, 
from  below.  As  the  liquid  enters  the  tank  the  air  is  compressed, 
and  this  allows  a  large  amount  of  fluid  to  enter.  Most  of  these 
pumps  are  made  so  that  they  will  withstand  160  pounds  of 
pressure,  a  steam  gauge,  G,  being  fastened  to  the  tank  of  each 


FIG.  12.  —  A  new  type  of  spray 
pump. 


Spraying  Devices  and  Machinery. 


193 


pump  to  indicate  the  pressure 
under  which  the  work  of  spraying 
is  done.  These  pumps  are  made 
of  different  sizes. 

The  Nixon  Nozzle  &  Machine 
Co.,  Dayton,  O.,  was  the  first  to 
manufacture  a  geared  spraying 
machine.  It  was  called  the  "  Field 
and  Orchard  Machine,"  and  was 
designed  by  A.  H.  Nixon,  the 
founder  of  the  firm.  The  machine 
was  introduced  in  1887,  it  being 
sent  to  several  persons  to  be  tested. 
In  1888  it  was  offered  to  the  pub- 
lic. Fig.  14  illustrates  the  general 
construction  of  the  machine  as  first 
sold.  It  will  be  noticed  that  the 
four  nozzles  are  situated  in  front 
of  the  wheels,  instead  of  at  the 
rear  as  is  now  generally  the  case. 
The  tank  held  100  gallons,  and 
was  built  in  the  form  of  a  cube, 
instead  of  barrel-shaped.  The 
price  was  seventy-fhe  dollars. 


FIG.  13.  —  Pneumatic  spray  pump. 


FIG.  14.  —The  first  geared  spray  machine  advertised  in  America. 
O 


194 


The  Spraying  of  Plants. 


Various  excellent  machines  of  this  type  are  now  manufac- 
tured by  several  firms. 

During  the  past  few  years,  many  machines  adapted  to  the 
spraying  of  potatoes  and  other  low-growing  plants  have  been 
manufactured.  They  are  of  two  kinds :  First,  those  in  which 
the  flow  of  liquid  is  produced  by  gravity ;  second,  those  in  which 
the  fluid  is  forced  through  the  outlet  orifice  with  the  aid  of  a 
pump.  Some  of  the  machines  belonging  to  the  first  class  break 


FIG.  15.  — The  first  successful  spraying  outfit  using  steam  power. 


up  the  liquid  by  means  of  revolving  brushes,1  or  by  a  blast 
of  air,2"  but  the  majority  are  modifications  of  common  street 
sprinklers. 

The  second  class  includes  both  hand  pumps  and  power 
machines,  and  as  a  rule  these  are  the  most  satisfactory.  Less 
trouble  is  experienced  from  clogging,  and  more  uniform  appli- 
cations may  be  made.  One  of  the  first  machines  of  this  charac- 
ter was  the  "  Climax,"  this  having  been  sold  in  1890.  It  was 
manufactured  by  Thomas  Peppier,  Hightstown,  N.J.,  and  is 

i  J.  E.  Steitz,  Cudahy,  Wis.      2  Seth  K.  Samms,  Byberry,  Philadelphia,  Penn. 


Spraying  Devices  and  Machinery.  195 

still  upon  the  market  in  an  improved  form.  In  1895  the  Dem- 
ing  M'f 'g  Co.,  Salem,  O.,  first  made  the  "  Monarch,"  a  powerful 
machine,  which  is  also  suitable  for  vineyard  work. 

The  first  successful  use  of  steam  power  for  spraying  was 
made,  so  far  as  I  have  been  able  to  learn,  by  Stephen  Hoyt, 
Xew  Canaan,  Conn.  The  outfit  (Figs.  15  and  16)  was  first 
operated  in  1894,  and  the  following  year  it  was  again  used  with 
most  satisfactory  results.1  Large  shade  trees  were  sprayed 
thoroughly  and  rapidly  by  the  outfit.  Mr.  Hoyt  writes  me  as 
follows  regarding  its  operation : 


FIG.  16.  —  Tank,  boiler,  and  pump  of  the  outfit  shown  in  Fig.  15. 

"  The  machine  is  made  to  throw  four  streams,  two  of  which 
are  to  work  at  the  same  time ;  two  men  are  to  go  up  the  trees 
to  the  crotch  and  spray,  while  the  other  two  are  either  preparing 
to  go  up  the  next  or  are  coming  down  from  the  two  which  they 
have  sprayed.  The  hose  is  fixed  so  as  to  shut  any  one  of  them 
off  at  any  time,  and  so  when  two  of  the  men  are  through  spray- 
ing, the  other  two  can  start  or  keep  on  as  they  choose. 

"  The  two  streams  in  the  picture  have  a  water  pressure  of  from 
125  to  150  pounds  per  square  inch,  and  with  a  steam  pressure 

i  Connecticut  Agric.  Exp.  Sta.  1895,  July,  Bull.  121,  4. 


196  The  Spraying  of  Plants. 

of  100  pounds.  We  can  produce  a  spraying  pressure  of  over 
200  pounds,  but  is  not  necessary  as  it  is  too  big  a  strain  on  the 
hose.  I  have  had  three  streams  going  at  one  time  with  a 
water  pressure  of  100  pounds. 

"  We  use  the  McGowen  nozzle,  it  being  the  most  economical 
and  does  not  use  so  much  of  the  liquid  as  some  others,  and  if 
necessary,  can  make  the  spray  nothing  but  a  mist.  But  for  elm- 
tree  spraying  we  use  the  McGowen  straight  stream,  as  the  pres- 
sure is  so  great  that  it  tears  the  stream  into  a  good  spray  for 
tree  spraying." 

Various  modifications  and  improvements  have  already  been 
suggested  for  the  above,  and  the  time  must  soon  come  when 
some  such  apparatus  will  be  generally  employed  for  preserving 
the  long-suffering  shade  trees  of  our  cities  from  the  ravages  of 
insects.  The  smooth  roads  will  allow  the  use  of  heavier  and 
more  simple  machinery  than  could  be  worked  in  many  of  our 
large  orchards.  The  cost  of  the  treatments  would  be  distributed 
among  so  many,  and  the  benefits  derived  would  be  so  great, 
that  such  outfits  may  soon  come  into  general  use. 

Gas  engines  have  also  been  employed.  During  1895,  W. 
R.  Gunnis,  of  San  Diego  County,  Cal.,  applied  kerosene  emul- 
sion to  his  trees,  using  power  of  this  nature.  "  The  appa- 
ratus is  placed  on  the  platform  of  a  light  wagon,  and  on  the 
front  end  is  a  tank  of  a  capacity  of  100  gallons,  filled  with  the 
emulsion.  A  small  electro-vapor  engine  on  the  wagon  operates 
a  double-action,  high-pressure,  cylinder  pump,  and  to  this  eight 
lines  of  hose  may  be  attached.  The  pump  can  be  worked  at  a 
pressure  of  200  pounds,  rendering  the  spray  fine  and  strong, 
and  capable  of  reaching  to  the  tops  of  the  tallest  trees,  where 
the  hose  is  supported  by  ten-foot  bamboo  canes.  Twenty-five 
or  thirty  acres  of  four-year  old  trees  may  be  sprayed  in  one  day 
with  the  labor  of  four  men." 1 

A  device  for  mixing  kerosene  and  water  has  been  invented 
by  Professor  Goff,  and  during  1894  the  Nixon  Nozzle  & 
Machine  Co.  offered  it  for  sale  in  connection  with  the  "  Climax  " 
pump,  and  other  firms  attached  it  in  a  modified  form  to  knap- 
sack sprayers.  Experiments  for  obtaining  such  a  mixture  had 
been  made  in  1888,2  but  it  was  not  until  about  the  year  1893 

i  Insect  Life,  1S95,  vii.  No.  5,  413. 

«  Goff,  N.  Y.  State  Agrio.  Exp,  Sta.  Ann.  Kept,  1888, 148. 


Spraying  Devices  and  Machinery.  197 


that  dealers  considered  the  matter  seriously.  The  principle 
underlying  the  construction  of  the  apparatus  is  that  the  move- 
ment of  the  piston  draws  into  the  cylinder  a  certain  amount 
of  water  through  one 
opening,  but  through 
a  second  one  kerosene 
is  drawn  in.  The  two 
liquids  become  intimate- 
ly mixed  by  their  pas- 
sage through  the  pump 
before  being  thrown 
from  the  nozzle,  and 
thus  a  dilute  kerosene 
may  be  evenly  applied. 
The  flow  of  kerosene 
into  the  cylinder  may 
be  regulated  by  a  stop- 
cock.1 An  improved 
form  of  such  an  attach- 


FIG.  17.  —  An  improved  form  of  a  kerosene  reser- 
voir attached  to  a  knapsack  pump. 


inent  on  a  .  knapsack 
pump  is  shown  in  Fig. 
17.  The  Demiug  Co., 
of  Salem.  O.,  and  Professor  H.  E.  Weed,  of  Agricultural  Col- 
lege, Mississippi,  have  been  most  active  in  perfecting  these 
machines. 


II.   EVOLUTION  OF  NOZZLES. 

The  production  of  the  spray  nozzle  is  one  of  the  most  inter- 
esting of  the  many  problems  which  have  taxed  the  ingenuity 
of  inventors.  So  long  as  the  materials  applied  were  in  the  form 
of  clear  liquids,  or  when  they  were  used  only  in  small  quantities, 
not  much  attention  was  paid  to  this  part  of  the  machines.  But 
with  the  use  of  the  garden  engine  and  force  pump,  and  more 
dense  fluids,  there  also  arose  the  demand  for  proper  devices  by 
means  of  which  the  liquid  thrown  could  be  broken  up  more  or 
less  finely. 

The  simplest,  and  probably  the  first  form  of  nozzle  was  one 

*  See  also  Wit.  Agric.  Exp.  Sta.  Ann.  Sept.  1891,  162,  and  Garden  and 
Forest,  vii.  1895, 143. 


198  The  Spraying  of  Plants. 

which  would  throw  a  solid  stream.  It  was  constructed  so  that 
the  volume  of  liquid  was  gradually  contracted  as  it  approached 
the  outlet  orifice,  and  the  stream  was  not  broken  up  until  it  had 
been  carried  some  distance  from  the  nozzle.  The  stream  was 
often  changed  to  a  spray  by  screwing  a  rose,  or  some  similar 
device,  to  the  end  of  the  nozzle.  The  openings  in  these  attachr 
ments  still  allowed  the  passage  of  solid  streams  of  liquid,  but 
these  were  so  reduced  in  size  that  the  fluid  was  broken  up  into 
much  smaller  drops. 

Three  principles  have  been  utilized  in  the  construction  of  all 
spray  nozzles  now  in  use.  These  principles  form  a  basis  for 
the  natural  division  of  nozzles  into  three  main  groups,  these 
allowing  of  still  further  subdivision  : 

1.  Spray  nozzles  in  which  the  stream  is  more  or  less  broken 
directly  in  consequence  of  the  modifying  action  of  the  margins 
of  the  outlet  orifice. 

2.  Spray  nozzles  in  which  the  stream,  having  passed  the 
outlet  orifice  proper,  is  modified  by  obstructions  which  affect 
its  free  and  direct  outward  passage. 

3.  Spray  nozzles  in  which  a  strong  rotary  motion  is  given 
to  the  liquid,  and  in  consequence  of  this  motion,  the  stream 
leaving  the  outlet  orifice  immediately  assumes  the  form  of  a 
spray. 

These  principles  are  mentioned  in  the  order  in  which  they 
probably  came  into  use.  Some  of  the  later  nozzles  combine 
the  first  two  principles,  and  others  seem  to  form  a  connection 
between  them,  although  one  principle  or  the  other  strongly 
predominates.  Some  of  the  nozzles  belonging  to  the  various 
groups  are  here  briefly  considered.1 

The  first  group  was  long  represented  by  nozzles  throwing  a 
solid  stream,  the  outlet  orifice  being  circular.  A  new  type  of 
nozzles,  a  modification  of  these,  began  to  be  made  about  1875. 
This  class  became  known  as  graduating  spray  nozzles,  from  the 
fact  that  the  character  of  the  liquid  thrown  could  be  varied 
from  a  solid  stream  to  that  of  a  fine  spray,  by  introducing  into 
the  outlet  orifice  a  pointed  piece  of  metal  or  lance.  This  entered 
the  orifice  from  the  inner  side,  and  the  further  it  was  intro- 
duced, the  smaller  became  the  opening  and  the  finer  was  the 

1  For  a  more  complete  description,  with  illustrations,  of  many  of  the  nozzles 
here  mentioned,  see  American  Gardening,  1893,  May,  266. 


Spraying  Devices  and  Machinery.  199 


spray.  It  was  moved  by  turning  some  part  of  the  nozzle  which 
was  connected  with  the  lance.  The  "Peerless,"  "Lowell,"  and 
"  Gem  "  (Fig.  18  a)  are  good  examples  of  this  class. 

In  1878  a  patent  was  granted  to  the  Belknap  Company  on  a 
new  nozzle  called  the  "  Boss  "  (Fig.  18  5).  It  has  two  outlet 
orifices,  and  the  stream  is  directed  into  the  one  or  the  other  by 
means  of  a  hollow  stopcock  which  is  perforated  in  such  a  man- 
ner that  it  partially  or  entirely  closes  one  or  both  of  the  open- 
ings. The  "Eureka,"  "Masson,"  and  "Bordeaux"  (Fig.  18  c) 
are  modified  forms  which  have  since  appeared.  The  spray  is 
varied  by  changing  the  size  of 
the  opening,  this  being  easily 
done  by  turning  the  perforated 
stopcock. 

In  1858  Rumsey  &  Co.  adver- 
tised a  nozzle  called  the  "  Fan- 
tail"  (see  Fig.  5).  It  consisted 
of  a  flat  spreading  tip  having  a 
long,  narrow  opening  which  dis- 
charged the  liquid  in  the  form 
of  a  spray  resembling  in  outline 
the  ilame  of  a  gas  jet.  This 
principle  of  having  the  liquid 
issue  between  two  flat,  parallel 
pieces  of  metal  has  been  retained 
in  more  or  less  modified  form 
in  many  of  the  nozzles  now  in 
use.  One  of  the  most  primitive 
forms  was  made  by  hammering  a  nozzle  designed  to  throw  a 
solid  stream  in  such  a  manner  that  the  opening  was  long  and 
narrow  instead  of  circular.  It  was  even  recommended  that 
they  should  be  made  in  this  manner.1  Little  was  done  towards 
improving  this  class  of  nozzles  until  about  1889,  when  a  patent 
was  granted  on  the  "Xew  Bean."  In  this  nozzle  the  width  of 
the  opening  could  be  adjusted  by  means  of  a  screw,  one  side  of 
the  orifice  being  of  rubber  packing.  In  1890  Bailey  published 
a  description  of  a  device,  by  means  of  which  the  end  of  a  hose 
could  be  contracted  so  that  a  fan-shaped  spray  was  produced  2 

1  Cullitator  and  Country  Gentleman,  1871,  Aug.  3,  486. 
»  Cornell  Agric.  E®p.  Sta.  1890,  July,  Bull.  18,  39. 


FIG.  18.  —  Spray  nozzles,  a,  gradu- 
ating spray  "Gem";  6,  "Boss"; 
c,  "  Bordeaux." 


200 


The  Spraying  of  Plants. 


(Fig.  19  a).  The  size  of  the  opening  was  entirely  under  the 
control  of  the  operator,  and  in  case  of  clogging  it  could  be 
opened  to  its  fullest  extent. 

It  was  about  this  time  that  the  "  Wellhouse  "  nozzle  was  first 
made  *  (Fig.  19  6).  It  is  made  after  the  pattern  of  a  gas  jet, 
but  much  larger. 

In  1892  the  first  automatic  cleaning  nozzle  was  invented 
(Fig.  19  d),  it  having  been  suggested  by  the  device  shown  in 
Fig.  19  c.  It  has  since  been  offered  for  sale,  in  a  modified 


FIG.  19.  —  a,  "  Bailey  "  ;   b,  "  Wellhouse  "  ;   c  and  d,  forms  which  led  to  the  con- 
struction of  e,  the  "McGowen." 

form,  having  been  named  the  "McGowen,"  after  its  inventor.2 
In  this  nozzle  (Fig.  19  e)  the  opening  is  formed  by  two  pieces 
of  metal  which  remain  in  contact  when  not  in  use.  One  piece 
is  movable  and  is  in  the  form  of  a  piston  which  moves  back- 
ward and  forward  in  a  cylinder  placed  at  right  angles  to  the 
main  shaft.  As  the  pressure  in  the  shaft  increases,  the  size  of 
the  opening  enlarges,  and  in  this  manner  any  obstruction  which 
may  become  lodged  at  the  outlet  orifice  will  cause  an  increase 

1  Invented  by  Walter  Wellhouse,  Fairmount,  Kan.    See  a  full  illustrated  account 
in  Hep.  Kan.  Hort.'Soc.  xviii.  99. 
>  John  J.  McGowen,  Ithaca,  N.  Y, 


Spraying  Devices  and  Machinery.  201 


of  pressure  which  forces  the  piston  back  to  its  fullest  extent, 
thus  allowing  the  passage  of  the  obstruction.  This  nozzle  is 
in  many  respects  a  radical  departure  from  all  forms  made  at 
the  time  of  its  introduction,  and  its  automatic  action  marks  it 
as  a  distinct  advance  in  the  evolution  of  spray  nozzles. 

The  second  group  of  nozzles,  including  those  in  which  the 
stream  of  liquid  is  broken  by  some  obstruction  preventing  its 
free  outward  passage,  is  represented  by  fewer  specimens  than  is 
either  one  of  the  others.  Although  such  nozzles  were  among 
the  first  made,  their  construc- 
tion apparently  does  not  admit 
of  so  many  modifications  as  are 
feasible  in  the  other  groups. 

The  form  first  sold  was  known 
as  a  "Diffuser."  It  was  made 
by  extending  a  portion  of  one 
side  of  the  outlet  orifice  into  a 
broad,  fan-shaped  piece  of  metal 
against  which  the  liquid  was 
thrown  at  a  very  slight  angle. 
This  caused  the  stream  to  spread 
over  the  surface  of  the  projec- 
tion, and  in  this  manner  it  was 
broken  up  into  a  coarse  spray. 
Fig.  20  a  represents  a  form  at 
present  used  in  France,  the 
"Vigouroux."  The  fan-shaped 
projection  has  in  recent  years 
been  so  constructed  that  it  may 
be  brought  close  to  the  orifice  or  it  can  be  removed  entirely1 
(Fig.  20&).  It  is  generally  made  of  metal,  but  there  is  now 
sold  one  form  in  which  a  piece  of  rubber  answers  the  same 
purpose.  The  rubber  is  pressed  over  the  opening  in  the  nozzle, 
and  the  size  of  the  orifice  as  well  as  the  character  of  the  spray 
may  be  varied  to  a  considerable  extent. 

In  1884  a  patent  was  granted  to  the  Nixon  Nozzle  &  Machine 
Co.,2  on  a  nozzle  known  as  the  "  Climax,"  in  which  the  liquid 
was  forcibly  thrown  as  a  solid  stream  against  a  piece  of  wire 

i  P.  C.  Lewis  Manufacturing  Co.  Catskill,  N.  Y. 
*  Nixon  Nozzle  &  Machine  Co.  Dayton,  O. 


FIG.  20.  —  a,  "  Vigouroux  " 
b,  "  Lewis  "  ;  c,  "  Climax  " 
d,  "  Ball." 


202  The  Spraying  of  Plants. 

gauze  (Fig.  20  c).  It  was  here  broken  up  into  a  spray  varying  in 
character  with  the  size  of  the  meshes  in  the  wire  netting.  These 
nozzles  were  widely  recommended  and  sold,  and  they  are  the 
most  important  which  can  at  present  be  found  in  this  group. 

The  "Ball"  nozzle  (Fig.  20 d)  is  a  new  modification  which 
was  first  extensively  advertised  in  1895.  At  the  end  of  a  hose 
is  fastened  a  hollow  conical  piece  of  metal  in  which  a  light  ball 
loosely  rests.  As  the  liquid  is  forced  against  the  ball  the  latter 
is  not  ejected,  but  remains  to  break  up  the  fluid  into  a  fairly 
light  spray.  The  serious  objection  to  the  device  is  the  amount 
of  power  required  to  throw  even  a  moderate  amount  of  fluid.1 

There  is  another  class  which  may  be  included  here.  It  is 
composed  of  those  nozzles  in  which  the  obstruction  is  not  a 
solid,  but  consists  of  a  stream  of  liquid.  Two  openings  are 
made  at  the  outer  extremity  of  the  nozzle,  and  these  incline 
toward  each  other  in  such  a  manner  that  the  two  streams 
issuing  from  them  come  forcibly  in  contact  with  each  other, 
and  are  immediately  changed  to  a  fine  spray.  The  "  Lilly," 
or  "  Calla,"  and  one  modification  of  the  "  McGowen,"  are  good 
examples  of  this  form. 

The  history  of  the  third  group  of  nozzles  is  very  recent,  yet 
many  forms  have  been  produced.  Several  of  the  most  popular 
nozzles  now  in  use  may  here  be  classified  together.  They  are 
collectively  knowri  as  the  cyclone  or  eddy-chamber  nozzles, 
from  the  fact  that  the  liquid,  upon  entering  the  nozzle,  is 
forced  to  whirl  with  great  rapidity  in  a  circular  chamber 
before  it  passes  through  the  outlet  orifice.  This  cyclonic 
motion  causes  the  fluid  to  be  broken  up  into  particles  which 
vary  in  size  with  the  size  of  the  opening,  the  smaller  orifices 
causing  the  formation  of  a  spray  which  is  exceedingly  fine,  so 
fine  that  it  floats  in  the  air  like  steam,  and  does  not  fall  to  the 
ground. 

William  S.  Barnard  appears  to  have  been  the  first  to  conceive 
the  idea  of  making  spray  nozzles  in  which  the  above  principle 
should  be  utilized.2  During  the  summer  of  1880  he  was 


1  American  Ball  Nozzle  Co.  S37-84T  Broadway,  N. Y. 

2  "  On  such  evidence  it  must  be  held  that  Barnard  originated  the  basic  idea  of  the 
improvement  in  question."    Decision  of  the  Commissioner  of  Patents  and  of  U.  S. 
Courts  in  Patent  Cases  as  recorded  in  The  Official  Gazette,  of  the  U.  S.  Patent 
Office,  Vol.  59,  No.  12,  1922. 


Spraying  Devices  and  Machinery.  203 


engaged  as  an  agent  of  the  United  States  Entomological  Com- 
mission, and  was  stationed  in  the  South  to  conduct  experiments 
for  the  destruction  of  the  cotton-worm.  It  was  probably  while 
engaged  in  the  \vork  of  throwing  liquids  that  the  idea  suggested 
itself,  and  that  it  was  soon  put  into  execution  is  shown  by  an 
affidavit  made  by  Professor  C .  V.  Riley,  April  14, 1886.1  During 
1880  the  principle  was  tested  with  the  aid  of  watch  crystals,  these 
being  chosen  from  the  fact  that  in  them  the  action  of  the  liquid 
could  be  easily  observed.  Other  contrivances  were  also  em- 
ployed, and  thus  began  the  series  which  eventually  led  to  the 
construction  of  the  nozzle  that  became 
widely  known  as  the  "  Riley,"  "Cy- 
clone," or  "  Eddy-chamber  "  spray  nozzle 
(Fig.  21  a).  Unfortunately,  the  name 
"  Barnard  "  has  not  been  more  closely 
connected  with  the  invention,  which  is 
without  doubt  one  of  the  most  impor- 
tant of  the  many  bearing  on  the  subject 
of  spraying.  The  nozzle  was  briefly 
mentioned  in  the  annual  report  of  the 
United  States  Commissioner  of  Agri- 
culture for  1881-82,  and  again  in  the 
report  of  1884.  In  the  latter  report,  on 
page  330,  Dr.  Riley  makes  the  following 
statement :  "  The  final  form  of  chamber 
adopted  is  the  result  of  numberless  ex- 
periments carried  on  by  Dr.  Barnard  in 
my  work,  both  for  the  United  States 
Entomological  Commission  and  the  De- 
partment of  Agriculture." 

Dr.  Riley  visited  France  in  1884,  and  in  an  address  delivered 
June  30,  to  the  Societe  Centrale  d' Agriculture  de  1'Herault,  he 
mentioned  Barnard's  nozzle,  and  this  no  doubt  hastened  its 
adoption  in  that  country.2  The  nozzle  was  easily  clogged,  and 
on  this  account  it  gave  considerable  trouble,  yet  it  was  conceded 
to  be  one  of  the  best,  and  was  used  by  several  experimenters  in 
1885.  It  attracted  the  attention  of  French  manufacturers, 
the  firm  of  V.  Vermorel,  Yillefranche  (Rhone),  being  perhaps 

»  Official  Gazette  U.  S.  Patent  Office,  Yol.  59,  No.  12,  1922. 
Agricole,  1SS4,  July  10,  261. 


1 


FIG.  21.— a,  "Cyclone"; 
&,  old  form  of  "  Yermo- 
rel "  ;  c,  modified  form 
of  "  Yermorel." 


204  The  Spraying  of  Plants. 

the  first  to  manufacture  this  nozzle,  which  is  there  called  the 
"Riley."  Vermorel  informs  me  that  it  was  during  1886  and 
1887  that  he  added  the  attachment  by  means  of  which  the  out- 
let orifice  can  be  cleaned  when  it  becomes  clogged.  The  improve- 
ment consists  of  a  pin  or  lance  which  can  be  pressed  forward 
until  the  point  penetrates  the  orifice  and  thereby  forces  outward 
all  obstructions.  Fig.  21  b  represents  one  of  the  earlier  forms. 
Vermorel  also  made  a  few  minor  changes  during  1889  and  1890. 
His  improved  form  of  the  cyclone  nozzle  became  known  as  the 
"  Vermorel,"  and  it  was  almost  immediately  adopted  in  America, 
to  the  exclusion  of  the  older  forms  made  by  Barnard.  The 
name  "  Vermorel "  has  also  been  retained.  The  nozzle  is  at 
present  one  of  the  best  in  use.  Although  many  modifications 
of  it  have  been  made,  the  original  form  is  fully  as  serviceable 
as  the  later  ones,  and  it  is  generally  preferred.1 

The  elbow  in  the  Vermorel  nozzle  is  one  feature  which  is 
open  to  slight  objection,  and  many  attempts  have  been  made  to 
avoid  it  (Fig.  21  c).  Several  nozzles  have  also  been  made  in 
which  the  eddy  chamber  and  outlet  orifice  are  situated  directly 
in  line  with  the  main  shaft.  These  nozzles  look  a  little  neater, 
and  they  are  more  easily  moved  about  among  branches,  but  in 
other  respects  they  possess  no  advantage.  The  spray  as  a  rule 
is  no  better  than  that  of  the  true  Vermorel,  and  the  parts  are 
cleaned  with  greater  difficulty  in  case  of  clogging.  The  class 
is  represented  by  the  "Marseilles,"  "Bean's  Cyclone,"  "Myers," 
"  Acme,"  and  others. 

Vermorel  nozzles  are  also  made  with  a  shaft  about  eighteen 
inches  long.  Connections  are  made  with  the  lance  which 
cleans  the  orifice  by  means  of  a  rod  which  is  operated  by  a  lever. 
This  form  is  used  almost  wholly  with  knapsack  pumps. 

III.   BELLOWS  AND  POWDER  GUNS. 

Powders  have  long  been  used  for  the  control  of  fungi  and 
insects.  In  Europe  sulphur  was  generally  so  applied,  previous  to 
1885,  against  the  grape  mildew,  and  special  apparatus  had  been 
devised  for  making  these  applications.  The  most  popular 
instrument  for  the  purpose  was  a  hand  bellows,  upon  which 

1  For  French  modifications  of  the  cyclone  nozzle,  see  Riley,  Insect  Life,  1889, 
Vol.  i.  No.  8,  243 ;  and  lUd.  No.  9,  263. 


Spraying  Devices  and  Machinery.  205 


FIG.  22.  —  Hand  bellows  for  blowing  powders 


was  fastened  a  small  reservoir  for  holding  the  material 
(Fig.  22).  Bellows  are  easily  operated,  distribute  the  powders 
evenly,  and  in  ad- 
dition are  cheap, 
so  they  are  still 
very  commonly 
used,  in  modified 
and  improved 
form,  both  in  Eu- 
rope and  in  this 
country.  When 
large  areas  are  to 
be  treated,  however,  the  work  progresses  but  slowly,  and  this 
has  led  to  the  invention  of  machines  which  force  a  current  of 
air  through  a  tube  by  means  of  a  revolving  fan,  the  powder 
being  mixed  with  the  air.  A  type  of  this  class  of  machines  is 
shown  in  Fig.  23.  Their  action  is  certain  and  rapid,  and 
although  they  are  more  expensive,  their  greater  effectiveness 

well  warrants  the  outlay. 
The  first  powder  gun  made 
in  America  appears  to  have 
been  invented  by  Legget, 
who  began  its  manufacture 
as  early  as  1854. 

Another  advance  was 
made  in  1895,  when  there 
was  advertised  a  horse- 

FIG.  23.  — Gun  for  applying  powders  rapidly,     power  machine  called  the 

"Sirocco  Dust  Sprayer."  1 

A  powerful  air  blast  is  produced  by  gearing  a  revolving  fan  to 
the  main  wheels,  and  large  amounts  of  any  dry  powder  may 
be  quickly  and  evenly  distributed. 


IV.    COMPARISON  OF  LIQUIDS  AND  POWDERS. 

Having  thus  very  briefly  discussed  the  gradual  introduction 
and  development  of  the  machinery  used  in  making  applications 
of  insecticides  and  fungicides,  it  now  remains  to  discuss  the 


1  The  Sirocco  Company,  Unionville,  Lake  County,  O. 
by  W.  K.  Monroe. 


The  device  was  invented 


206  The  Spraying  of  Plants. 

all-important  question,  "Which  is  the  best?"  Before  going 
into  details  it  may  be  well  to  obtain  a  clear  idea  with  regard 
to  the  comparative  value  of  liquids  and  powders. 

Powders  are  more  easily  handled  than  liquids,  and  with  the 
machinery  now  made  they  can  be  just  as  evenly  applied  ;  yet  it 
is  only  in  exceptional  cases  that  their  use  is  advisable.  Powders 
cannot  be  thrown  any  considerable  distance,  and  this  neces- 
sarily limits  their  profitable  application  to  the  lower  growing 
plants.  This  becomes  especially  emphatic  when  a  wind  is 
blowing,  for  every  current  of  air  will  change  the  direction  in 
which  the  particles  move,  and  a  considerable  loss  of  material 
will  take  place.  A  quiet  day  is  therefore  generally  the  best  for 
making  such  applications. 

Another  defect  is  that  powders  cannot  always  be  made  to 
adhere  so  firmly  to  foliage  as  the  liquid  applications  do.  When 
the  foliage  is  dry  it  commonly  occurs  that  scarcely  any  of  the 
powders  will  adhere,  and  this  necessitates  wetting  the  parts  to 
be  treated,  or  else  waiting  until  dew  or  rain  shall  have  moistened 
them  so  that  the  particles  will  remain  where  they  are  applied. 
Plants  having  smooth  foliage  are  particularly  difficult  to  treat. 
Another  objection,  and  so  far  as  fungous  diseases  are  concerned, 
the  most  serious  one,  is  that  we  have  no  powders  which  are  as 
effective  as  the  liquids,  and  for  this  reason  alone  the  latter  are 
to  be  preferred.  With  insecticides,  however,  the  case  is  different. 
The  best  insecticides  are  in  powder  form,  and  when  low-grow- 
ing, rough-leaved  plants  are  treated  while  the  foliage  is  damp, 
the  poisons  can  be  profitably  and  economically  applied.  Plants 
grown  in  greenhouses  can  also  be  successfully  treated  in  the 
same  manner,  since  here  there  are  almost  no  air  currents,  and 
the  moisture  may  be  controlled  with  ease. 

Liquids  can  be  applied  under  nearly  all  circumstances.  If 
proper  machinery  is  used,  it  makes  comparatively  little  differ- 
ence whether  the  plants  are  one  or  thirty  feet  high.  In  case 
of  a  wind  the  material  can  still  be  thrown,  although  not  so 
well,  and  the  operator  is  also  under  less  discomfort.  Liquids 
will  adhere  to  the  parts  to  which  they  are  applied,  with  only 
few  exceptions,  and  on  this  account  greater  protection  is 
afforded  by  them.  Both  fungicides  and  insecticides  can  be 
thrown  equally  well  by  the  same  appliances,  and  since  the  two 
are  generally  used,  it  would  seem  that  liquids  are  to  be  pre- 


Spraying  Devices  and  Machinery.  207 

ferred.     This  is  especially  true  when  several  different  crops  are 
to  be  treated. 

If  powders  are  preferred,  the  hand  bellows  will  be  found 
very  serviceable  when  only  a  small  area  is  to  be  covered.  For 
more  extensive  work,  machines  with  revolving  fans  to  produce 
stronger  air  blasts  will  answer  the  purpose  better,  since  the 
work  can  be  done  more  easily  and  also  more  rapidly. 


V.   MERITS  OF  THE  VARIOUS  SPRAYIXG  DEVICES. 

The  bulk  of  insecticides  and  fungicides  are  applied  in  liquid 
form,  and  so  much  machinery  for  making  the  applications  is 
offered  for  sale  that  the  selection  of  the  best  is  by  no  means 
an  easy  matter.  The  conditions  under  which  the  materials 
are  used  are  so  exceedingly  varied,  that  recommendations 
which  apply  in  one  case  have  little  value  in  another.  Only 
general  statements  can  be  made  with  safety,  and  each  indi- 
vidual must  select  that  which  in  his  judgment  promises  to  be 
most  effective.  Several  of  the  ideas  here  advanced  are  not  in 
accord  with  those  of  some  writers  whose  opinions  are  entitled 
to  very  careful  consideration ;  but  since  they  are  the  result 
of  personal  experience  and  observation  in  the  field,  and  of  ex- 
periment in  the  laboratory,  the  conclusions  reached  are  given 
with  the  belief  that  no  one  who  follows  them  will  go  far 
astray.  The  subject  is  the  more  difficult  to  treat  from  the  fact 
that  personal  bias  often  enters,  and  that  Mrhich  suits  one  man 
may  or  may  not  suit  another.  The  manufacturers'  side  must 
also  be  considered,  since  it  is  but  right  that  their  products 
should  be  justly  valued.  Unfortunately,  it  is  impossible  to 
enter  into  the  merits  and  defects  of  all  spraying  contrivances 
offered  for  sale ;  the  descriptions,  therefore,  will  apply  only  to 
the  types  of  the  more  important  groups. 

A  few  points  apply  in  the  selection  of  any  spraying  machine. 
As  a  rule,  it  is  better  to  have  all  working  parts  of  brass,  the 
body  of  the  pump  being  either  of  brass  or  of  iron.  The  alloy 
is  more  durable  than  iron,  since  it  is  not  so  easily  corroded  by 
the  liquids  used,  nor  by  exposure  to  air.  The  first  cost  is 
greater,  but  in  the  end  the  extra  price  is  well  spent.  All  brass, 
however,  is  not  suitable  for  spray  pumps.  Ammonia  water  has 


208  The  Spraying  of  Plants. 

a  strong  solvent  action  upon  soft  brass,  that  which  is  composed 
of  copper  and  zinc,  and  for  this  reason  such  brass  should  be 
avoided.  Hard  brass  is  an  alloy  in  which  more  or  less  tin  is 
used  with  the  copper ;  it  is  much  more  durable,  and  is  to  be 
preferred  in  the  construction  of  both  pumps  and  nozzles. 

Pump  valves  are  made  of  various  materials.  The  metal  ones 
are  to  be  preferred  as  a  rule,  although  glazed  ball  valves  are 
very  satisfactory.  Leather  is  freely  used  as  packing  and  in 
valves,  and  on  account  of  the  ease  with  which  it  can  be 
replaced,  it  is  not  objectionable.  Rubber,  however,  especially 
if  it  is  soft,  is  unsafe  to  use  in  a  spray  machine.  Kerosene  will 
cause  it  to  swell  to  such  an  extent  that  the  pump  is  rendered 
worthless  until  a  new  valve  is  put  in,  or  the  old  one  is  given 
time  to  shrink,  —  a  process  which  may  require  months. 

Knapsack  pumps  have  several  features  to  recommend  them. 
Liquids  can  in  this  manner  be  carried  and  applied  in  places 
inaccessible  to  wheeled  vehicles.  Vineyards  are  frequently  set 
in  such  locations,  as  are  also  espaliers  and  fruit-walls,  and  under 
such  conditions  a  knapsack  pump  has  no  equal.  On  small  home 
grounds,  where  the  nature  of  the  spraying  is  varied,  these 
pumps  may  also  be  used  to  advantage.  But  trees  cannot  be 
successfully  treated  by  them,  as  the  liquid  is  not  thrown  far 
enough.  Nor  is  their  use  in  even  moderately  large  plantations 
advisable,  since  the  labor  of  carrying  the  pump  is  onerous,  and 
the  machine  is  not  easily  operated.  Other  unpleasant  features 
will  also  be  forced  upon  the  man  who  works  the  machine,  and 
when  possible  a  different  device  should  be  preferred. 

Hand  syringes  are  practically  out  of  the  question  when  liquid 
applications  are  to  be  made,  except  in  case  of  plants  grown 
under  glass;  then  the  syringe  is  much  used,  although  water 
under  pressure  is  now  so  generally  piped  to  greenhouses  that 
even  here  the  use  of  syringes  is  steadily  decreasing,  the  more 
so,  since  a  stream  of  water  forcibly  applied  is  a  very  popular 
way  of  controlling  insect  pests.  Fungicides  may  be  applied  to 
plants  under  glass,  either  with  syringes  or  by  means  of  knap- 
sack or  bucket  pumps. 

Bucket  pumps,  such  as  represented  in  Fig.  24,  are  very  power- 
ful for  their  size,  and  they  will  throw  considerable  quantities 
of  liquid.  Moderate-sized  trees  may  be  thoroughly  treated  by 
them,  and  when  little  work  is  to  be  done  these  pumps  may  well 


Spraying  Devices  and  Machinery.  209 


be  substituted  for  the  knapsack  sprayers. 
Statements  are  frequently  seen,  asserting 
that  these  and  similar  pumps  may  be 
used  successfully  in  orchard  work,  and 
so  they  may.  But  the  work  is  so  tedious 
and  slow,  that  the  experiment  will  rarely 
be  tried  more  than  once.  A  larger  pump 
will  throw  a  greater  quantity  of  liquid  and 
throw  it  easier,  so  that  it  is  a  mistake  to 
purchase  a  small  pump  for  any  but  very 
limited  plantations.  Fig.  25  represents 
another  serviceable  pump  of  this  kind. 

The  greatest  variety  of  pumps  may  be 
found  among  those  which  are  suited  for  work  on  a  barrel,  or 


Vfcu 

FIG.  24.  —  Bucket  pump. 


FIG.  25.  —  Improved  bucket  pump. 

tank,  and  here  is  where  the  greatest  difficulty  occurs  in  making 
a  selection.     Items  of  cylinders,  pistons,  handles,  air  chambers, 


210  The  Spraying  of  Plants. 

agitators,  bases,  etc.,  require  attention,  and  as  they  are  all  of 
importance,  they  will  be  briefly  considered. 

Experience  has  led  to  the  conclusion  that  no  barrel  spray 
pump  should  have  a  cylinder  less  than  2%  inches  in  diameter, 
and  one  with  a  three-inch  cylinder  is  perhaps  to  be  preferred. 
This  assumes  that  more  than  one  nozzle  is  to  be  attached  to 
the  pump,  otherwise  a  smaller  pump  will  answer,  especially  if 
an  eddy-chamber  nozzle  is  used.  But  with  nozzles  designed  for 
heavier  work,  such  as  the  "  Wellhouse,"  the  "  McGowen,"  or  the 
"Bordeaux,"  the  above  dimensions  are  none  too  large.  The 
stroke  should  be  at  least  four  inches  in  length,  and  a  longer  one 
would  probably  be  better. 

Pistons  may  be  packed  with  leather  or  with  metal  rings. 
The  latter  are  more  durable,  but  the  wear  of  the  cylinder  is 
greater,  and  they  are  now  little  used  in  spray  pumps.  Leather 
or  candle-wicking  is  cheaper,  and  is  at  present  preferred. 

The  handle  of  a  pump  is  a  more  important  item  than  may  at 
first  be  supposed.  It  requires  considerable  force  to  move  a 
three-inch  piston  with  the  accompanying  body  of  water,  and  at 
the  same  time  to  drive  the  liquid  through  a  hose  and  nozzle 
with  such  force  that  it  shall  be  broken  into  a  spray.  If  the 
handle  is  long,  the  work  can  be  done  with  comparative  ease. 
By  a  long  handle  is  meant  one  which  is  from  25  to  30  inches 
from  the  pivot  to  the  outer  end,  the  distance  from  the  pivot  to 
the  piston-rod  being  from  four  to  five  inches  additional.  Full 
allowance  is  here  made  for  the  length  of  the  handle,  since  many 
are  made  which  are  faulty  in  this  respect. 

Air  chambers  have  been  almost  universally  regarded  with 
great  favor  both  by  the  manufacturers  of  pumps,  and  by  those 
who  purchase  apparatus.  The  strong  point  in  their  favor  is 
that  they  cause  a  more  uniform  flow  of  liquid,  which,  to  a  cer- 
tain extent,  is  highly  desirable.  The  question  is  entirely  one  of 
degree,  since  the  presence  of  an  air  cushion  unquestionably  pro- 
duces a  more  uniform  flow.  The  assertion  is  also  occasionally 
made  that  greater  power  may  be  obtained  by  the  use  of  an  air 
chamber,  and  that  in  consequence  the  spray  is  better  and  more 
easily  thrown.  Having  many  pumps  and  nozzles  at  my  dis- 
posal, the  different  sides  of  the  question  have  been  examined. 
Some  of  the  chambers  have  been  tapped  and  aircocks  inserted. 
Any  desired  amount  of  air  could  thus  be  displaced  by  the  water, 


Spraying  Devices  and  Machinery.  211 

or  the  chamber  could  be  completely  filled.  Different  styles  of 
nozzles  were  used  with  the  varying  capacity  of  the  air  cham- 
bers, so  that  the  experiments  might  be  as  conclusive  as  possible. 
A  sensitive  steam  gauge  was  also  attached  so  that  the  pressure 
could  be  measured. 

The  results  showed  that  no  greater  force  could  be  obtained 
whether  a  large  or  a  small  air  space  was  present ;  the  pump 
did  riot  appear  to  work  more  easily  with  a  large  chamber  than 
with  a  small  one,  nor  did  the  character  of  the  spray  appear  to 
be  modified.  A  great  difference  could  be  seen,  however,  in  the 
length  of  time  required  for  a  nozzle  to  throw  its  best  form  of 
spray,  since  the  character  of  the  spray  of  most  nozzles  varies 
with  the  pressure  of  the  liquid.  It  was  also  noticed  that  the 
flow  of  liquid  continued  much  longer  when  a  large  air  chamber 
was  attached,  but  as  the  pressure  decreased,  the  value  of  the 
spray  decreased,  so  that  only  the  main  flow  was  suitable  for 
making  applications.  As  many  nozzles  are  not  provided  with  a 
stopcock  for  shutting  off  the  flow  of  liquid,  there  is  more  or  less 
loss  of  material  whenever  the  pumping  ceases.  There  is  also 
a  loss  of  time  and  material  when  the  pressure  is  increased,  since 
the  flow  from  the  nozzle  is  delayed  as  the  capacity  of  the  air 
chamber  increases.  The  work  indicated  that  for  all  practical 
purposes  an  air  chamber  having  a  capacity  of  one  pint  to  one 
quart  is  sufficient  for  any  barrel  pump  or  for  any  nozzle.  It 
allows  a  quick  application  of  pressure,  and  its  almost  immediate 
removal,  while  the  air  cushion  is  sufficiently  large  to  produce  a 
uniform  spray. 

The  agitation  of  most  of  the  liquid  insecticides  and  fungi- 
cides is,  unfortunately,  necessary;  otherwise  the  undissolved 
particles  settle  at  the  bottom  of  the  tank,  and,  in  consequence, 
the  applications  are  uneven.  Even  a  knapsack  pump  will  not 
maintain  proper  agitation,  although  it  is  thoroughly  shaken  by 
the  man  carrying  it.  Some  certain  means  of  agitating  the 
liquid  must,  therefore,  be  adopted.  Attempts  have  been  made 
to  force  a  return  stream  of  the  liquid  into  the  barrel  or  tank, 
and  the  currents  so  produced  were  supposed  to  answer  the 
desired  purpose  (see  Fig.  28).  But  the  results  have  not  shown 
this  to  be  the  case,  and  this  class  of  agitators  is  being  gradu- 
ally abandoned.  Another,  and  more  effective,  method  is  to 
attach  a  paddle  or  dasher  to  the  handle  or  other  moving  part  of 


212 


The  Spraying  of  Plants. 


the  pump,  so  that  at  every  stroke  the  liquid  will  be  more  or  less 
thoroughly  stirred  (Fig.  29).  These  have  proved  successful  so 
far  as  the  agitation  is  concerned,  but  all  who  have  worked  a 
spray  pump  know  that  the  labor  is  sufficiently  severe  without 
the  addition  of  an  attachment  which  necessarily  consumes  con- 
siderable force.  Since  the  agitation  must  be  accomplished,  the 
use  of  some  of  these  devices  is  one  of  the  best  ways  out  of  the 
difficulty.  My  own  practice  has  been,  however,  to  insert  a  long- 
handled  paddle  into  the 
opening  through  which  the 
barrel  is  filled,  and  to  stir 
the  liquid  in  this  manner, 
directly  by  hand,  whenever 
it  is  necessary.  This  method 
is,  on  the  whole,  probably 
the  easiest  and  most  satis- 
factory. The  work  can  be 
done  as  thoroughly  as  de- 
sired, and  with  but  little 
extra  labor. 

The  liquid  contained  in 
large  barrels  or  tanks  can 
be  agitated  very  easily  by 
means  of  a  permanent  de- 
vice consisting  of  one  or 
more  paddles  which  are 
moved  by  a  lever  that  pro- 
jects above  the  reservoir. 
At  short  intervals  the  lever 
may  be  moved  until  the  fluid  is  thoroughly  stirred.  When  long 
tanks  are  employed,  several  paddles  should  extend  crosswise  of 
the  tank,  near  the  bottom,  and,  if  these  are  properly  connected, 
one  movement  of  the  lever  will  cause  a  movement  of  all  the 
paddles,  thus  quickly  and  easily  agitating  the  contents  of  the 
tank. 

If  a  pump  is  to  be  used  upon  a  barrel,  as  is  the  most  common 
practice,  the  base-casting  should  be  curved.  It  is  better  to  turn 
the  barrel  on  its  side  (Fig.  26)  and  fasten  the  pump  in  this 
manner.  When  it  lies  on  its  side,  the  sediment  collects  very 
near  one  central  point,  and  can  easily  be  dislodged  and  mixed 


FIG.  26.  —  A  spray  outfit,  the  pump  properly 
attached  to  the  barrel. 


Spraying  Devices  and  Machinery.  213 

with  the  water.  But,  if  the  barrel  is  on  end,  the  sediment  col- 
lects in  an  even  layer  over  the  entire  bottom,  and  it  is  much 
more  difficult  to  maintain  an  even  mixture.  Large  tanks  are 
unsatisfactory  in  this  respect,  since  the  bottom  is  generally  flat, 
and  it  is  difficult  to  reach  all  the  sediment  with  the  agitator. 
When  power  sprayers  are  used,  and  the  horse  does  the  pump- 


FIG.  27.  —  A  compact  and  powerful  spray  pump. 

ing,  it  does  not  make  so  much  difference  if  the  labor  is  harder, 
and  the  agitator  can  be  attached  to  a  moving  part  of  the  pump 
with  very  satisfactory  results. 

Fig.  27  represents  a  type  of  pump  sold  by  several  manufac- 
turers, which  answers  most  of  the  requirements  above  men- 
tioned. The  air  chamber  is  in  the  piston  rod,  where  it  is 
entirely  out  of  the  way,  yet  it  is  large  enough  for  all  practical 
purposes.  These  pumps  are  exceedingly  compact,  powerful,  and 


214 


The  Spraying  of  Plants. 


durable,  and  can  be  recommended  with  confidence.  Fig.  28 
illustrates  another  form  very  similar  to  the  preceding.  The 
air  chamber  surrounds  the  upper  half  of  the  pump,  causing  the 
enlargement.  These  two  pumps  are  amongst  the  most  compact 
and  serviceable  ones  now  sold. 


FIG.  28.  —  A  good  barrel  pump,  with  a  return  pipe  for  agitation,  and  a  strainer. 


Fig.  29  shows  a  style  of  pump  of  which  there  are  several 
modifications  (see  also  Fig.  34).  The  most  striking  feature  of 
this  type  is  the  very  large  air  chamber.  Many  of  these  sprayers 
are  in  use,  and  as  they  appear  to  give  satisfaction  they  must 
have  points  of  decided  merit.  Such  air  chambers  are  of  par- 
ticular value  upon  power  sprayers. 

Several  manufacturers  advertise  a  horizontal-acting  pump, 
as  shown  in  Fig.  30.  These  are  of  various  sizes,  the  cylinder 


Spraying  Devices  and  Machinery.  215 

not  being  smaller  than  2|  inches,  and  in  some  it  is  as  large  as 
5  inches  in  diameter.  These  pumps  are  little  used,  as  they 
seem  to  be  harder  to  operate,  and  they  are  limited  in  their  use 
more  than  the  forms  adapted  to  barrels. 


FIG.  29,  —  Spray  pump,  with  large  air  chamber ;  the  paddle  at  the  bottom  of  the 
barrel  acts  as  an  automatic  agitator. 


In  some  localities,  semi-rotary  pumps  (Fig.  31)  are  in  demand, 
no  other  form  being  thought  equally  effective.  The  action  of 
these  pumps,  when  new,  leaves  little  to  be  desired.  They  are 
easily  worked  and  powerful,  and  at  first  appear  to  approach  the 


FIG.  30.  — A  powerful  horizontal  spray  pump. 

216 


Spraying  Devices  and  Machinery.  217 

ideal  spray  pump.  Yet  the  manufacturers  have  admitted  that 
these  pumps  are  not  so  durable  as  the  other  styles,  and 
this  necessarily  follows  from  the  manner  of  their  construction. 


FIG.  81.  —Semi-rotary  or  "clock"  pump. 

They  are  also  more  delicate,  and  will  not  bear  the  abuse  which 
appears  to  have  no  effect  upon  other  forms.  When  clear  solu- 
tions are  applied  there  is  little  to  wear  the  inner  parts,  but  with 
gritty  preparations,  such  as  the  Bordeaux  mixture,  their  days  of 
service  are  not  very  long. 


218  The  Spraying  of  Plants. 

Later  and  improved  forms  of  the  pump  represented  by  Fig. 
12  have  been  extensively  used  during  the  season  of  1895,  with 
very  satisfactory  results.  One  cylinder  has  been  replaced  by  a 
metal  sheet,  which  is  fastened  at  the  base  of  the  pump,  but 
the  outer  end  is  free  to  be  carried  up  and  down  at  everv  stroke 
of  the  handle.  This  is  one  of  the  best  and  most  easily  operated 
agitators  with  which  I  am  acquainted,  and  the  pump  has  met 
with  much  favor,  although  but  recently  put  upon  the  market. 

Barrel  pumps  have  thus  far  proved  the  most  satisfactory  in 
spraying  old  orchards.  The  operation  is  too  slow  and  tedious 
when  smaller  pumps  are  employed,  and  geared  power  sprayers 
are  unable  to  cover  the  trees  with  sufficient  uniformity.  Engines 
have  not  as  yet  been  sufficiently  employed  to  warrant  their  rec- 
ommendation. When  trees  are  comparatively  small,  a  very 
serviceable  outfit  may  be  obtained  by  placing  the  barrel  and 
pump  on  a  light  wagon.  Two  men  can  work  most  conveniently. 
One  drives  and  pumps,  while  the  other  holds  the  nozzle,  or  the 
operations  may  be  differently  divided.  If  more  than  one  lead 
of  hose  is  in  use,  it  will  require  a  man  for  each  hose,  and  another 
to  pump. 

If  the  trees  are  large,  such  as  old  apple  trees,  an  outfit  similar 
to  that  shown  in  Fig.  32  will  prove  of  great  service.  One  man 
drives  and  pumps,  while  behind  him  is  the  barrel  or  tank.  The 
tank  may  be  of  various  shapes,  some  growers  preferring  hogs- 
heads, while  others  use  a  long,  low  tank,  having  a  flat  (Fig.  33) 
or  rounded  bottom,  the  latter  being  better,  as  the  liquid  can  be 
more  thoroughly  agitated.  Above  this  tank  is  a  platform, 
which  is  from  ten  to  fifteen  feet  from  the  ground.  The  men 
directing  the  spray  stand  upon  this,  and  are  prevented  from 
falling  by  a  rail  which  surrounds  the  platform.  This  elevation 
allows  the  spray  to  be  thrown  to  the  tops  of  very  high  trees, 
with  the  assistance  of  only  a  short  pole.  A  pole  is  an  unwieldy 
instrument  at  best,  and  if  proper  nozzles  are  used  it  may  be  dis- 
pensed with  in  the  majority  of  cases.  The  work  can  also  be 
more  thoroughly  accomplished  from  above,  as  the  parts  of  the 
tree  are  more  easily  reached,  and  the  liquid  does  not  fall  back 
upon  the  men,  as  so  frequently  occurs  when  the  spray  is  thrown 
from  lower  elevations.  The  man  who  drives  is  at  a  disadvan- 
tage, but  if  he  is  properly  protected  by  rubber  clothing,  the 
position  is  rendered  much  less  uncomfortable. 


FIG.  32.  —  An  excellent  spraying  outfit  for  tall  orchard  trees. 
219 


220 


The  Spraying  of  Plants. 


Many  orchards  are  so  thickly  planted  that  an  apparatus  like 
the  above  can  be  driven  through  only  with  great  difficulty.  In 
such  cases  the  branches  should  be  cut  so  that  the  orchard  may 
be  penetrated  in  at  least  one  direction.  With  good  apparatus 
the  trees  may  then  be  thoroughly  treated. 

Later  improvements  in  spraying  machinery  are  the  power 
sprayers,  of  which  Fig.  34  represents  one  of  the  best.  The 


FIG.  33.  —  A  good  rig  for  spraying  orchards. 

illustration  is  so  detailed  that  little  need  be  said  regarding  the 
construction  of  the  machine.  The  pumps  are  worked  by  means 
of  a  bar  which  is  fastened  to  a  crank.  The  crank  is  attached 
to  wheels  that  connect  with  the  large  wheels  by  means  of 
sprocket  chains,  and  motion  is  obtained  in  this  manner.  Fig. 
35  represents  another  type  of  machine  of  this  class.  The  liquid 
is  applied  by  means  of  a  rotary  pump.  Power  machines  are 
excellent  for  spraying  all  low-growing  plants  or  small  trees,  but 


Spraying  Devices  and  Machinery.  221 

the  best  work  cannot  be  done  in  a  bearing  apple  orchard,  and 
the  hand  pumps  must  be  depended  upon  for  the  most  efficient 
service.  But  for  potatoes,  nursery  stock,  vineyards,  orchards  of 
dwarf  trees,  these  machines  will  amply  repay  their  cost,  and 
with  proper  treatment  will  lessen  the  unpleasant  features  of 
spraying  to  a  very  great  degree.  Wherever  sufficient  work  is 
at  hand  to  warrant  their  purchase,  they  will  be  found  indispen- 
sable when  once  used. 


FIG.  34.  —  Power  sprayer.  A,  lever  attached  to  the  gearing ;  Z>,  bar  moved  by 
means  of  a  crank  attached  to  the  wheels ;  BB,  pumps  which  force  the  liquid 
into  the  discharge  hose ;  C,  tank. 

As  has  already  been  stated  on  page  194,  several  machines 
have  been  built  for  the  sole  purpose  of  spraying  potatoes.  As  a 
rule,  those  in  which  the  liquid  is  applied  with  the  aid  of  a  force 
pump  are  to  be  preferred,  although  excellent  machines  may  be 
found  among  those  in  which  the  liquid  flows  by  the  force  of 
gravity.  Some  method  of  converting  the  fluid  into  a  spray 
should,  however,  be  present.  Fig.  36  represents  a  machine  in 
which  this  is  done  by  means  of  a  revolving  brush,  BB.  Air 


The  Spraying  of  Plants. 

blasts  are  used  by  some  for  the  same  purpose  with  marked 
success. 

The  best  spray  nozzle,  so  far  as  efficiency,  simplicity,  and 
cheapness  are  concerned,  is  the  end  of  a  hose  and  a  man's 
thumb.  Unfortunately  the  thumb  gets  sore  and  tired,  and  opera- 
tions must  be  suspended  to  wait  for  repairs.  It  is  the  nearest 
approach  to  the  ideal  nozzle  yet  devised,  if  it  were  only  more 
practicable.  It  will  do  all  that  a  good  nozzle  should  do.  It 
throws  a  fine  mist-like  spray,  one  that  will  "float  in  the  air 


FIG.  35.  —  Power  sprayer,  with  rotary  pump. 

like  a  fog,"  or  the  particles  of  water  may  instantly  be  made 
coarser,  and  the  water  thus  carried  to  a  greater  distance;  or 
still  coarser  and  the  water  leave  the  hose  in  the  form  of  a  solid 
stream.  These  changes  all  take  place  instantly  (after  a  little 
practice),  and  it  makes  no  difference  whether  the  parts  to  be 
sprayed  are  a  few  inches  or  many  feet  away.  This  nozzle  never 
clogs,  but  is  cleaned  automatically,  and  as  quickly  as  the  char- 
acter of  the  spray  is  varied.  In  fact  it  possesses  all  the  desir- 
able qualities  of  a  spray  nozzle,  except  durability,  and  for  this 
we  must  turn  to  the  metals  for  aid. 


Spraying  Devices  and  Machinery.  223 

All  operators  do  not  desire  the  same  kind  of  spray  even  for 
the  same  kind  of  work.  It  is  commonly  said  that  the  best 
spray  is  one  which  most  nearly  resembles  a  fog.  This  is  true  so 
far  as  the  spray  is  concerned,  but  the  trouble  cornes  in  applying 
it.  A  fine  spray  cannot  be  applied  so  advantageously  as  a 
coarser  one,  nor  can  it  be  applied  so  rapidly  for  the  reason  that 
the  finer  the  spray  the  less  liquid  is  thrown,  and  the  smaller  the 
area  treated.  Whenever  the  wind  blows,  a  fog-like  spray  will  go 
wherever  the  wind  carries  it,  and  not  where  the  operator  directs 


FIG.  36.  —  Potato  sprayer ;  the  liquid  flows  by  the  force  of  gravity,  and  is  spread  by 
means  of  revolving  brushes,  BB ;  A,  rod  attached  to  agitator ;  T,  tank. 


it.  Sometimes  this  will  be  an  advantage.  It  is  especially  so 
when  the  wind  is  blowing  in  the  right  direction.  Yet  when  the 
other  side  of  the  tree  is  being  treated  the  wind  will  come  from 
the  wrong  direction,  and  much  of  the  material  is  blown  where 
it  is  not  wanted.  In  addition  to  this,  the  work  is  more  slowly 
performed,  and  whether  it  is  more  thoroughly  done  than  when 
a  coarser  spray  is  used  is  still  open  to  doubt.  After  having  tried 
both  kinds  of  sprays,  it  appears  to  the  writer  that  if  the  parts  to 
be  treated  are  close  by,  a  fine  spray  is  to  be  preferred,  as  then 
there  is  less  waste  and  an  even  application  may  be  made.  If 


224  The  Spraying  of  Plants. 

the  parts  to  be  treated  are  more  removed,  being  situated  from 
ten  to  twenty-five  feet  away,  a  coarser  spray  is  wanted;  —  the  more 
distant  the  object,  the  coarser  the  spray.  The  work  can  thus  be 
done  much  more  rapidly,  just  as  effectively  (with  the  exception 
of  some  waste),  and  much  more  satisfactorily,  than  by  the  use  of 
a  fine  spray.  In  case  a  fine  spray  is  used,  it  is  necessary  to  have 
a  pole  to  carry  the  nozzle  to  the  different  parts  of  the  tree,  and 
this  is  as  tedious  as  it  is  unpleasant.  When  a  coarser  spray  is 
made,  there  is  generally  formed  enough  of  the  finer  spray  to  float 
in  the  air  and  protect  parts  which  are  not  directly  reached  by 
the  operator. 

The  finest  sprays  are  produced  by  the  eddy-chamber  nozzles, 
and  by  those  in  which  two  streams  of  water  strike  each  other 
at  an  angle.  With  such  nozzles,  the  spray  can  be  made  as  fine 
as  desired,  the  size  of  the  outlet  orifice  being  the  main  control- 
ling factor.  For  long-distance  work,  when  the  liquid  is  to  be 
carried  ten  feet  or  more,  the  best  spray  is  formed  when  the  fluid 
is  forced  through  two  flat,  parallel,  metal  surfaces.  The  greater 
the  pressure,  the  greater  will  be  the  amount  of  fine  spray  and 
the  farther  will  it  be  thrown.  Although  the  ideal  nozzle  has 
not  yet  been  made  in  metal,  some  of  the  forms  now  sold  are 
approaching  perfection. 

All  good  spray  machinery  is  expensive,  and  only  careless 
operators  will  neglect  the  ordinary  methods  of  preserving  it 
as  long  as  possible.  When  the  pump  has  been  used  in  applying 
any  of  the  preparations  mentioned  in  Chapter  IV.,  with  the  ex- 
ception of  clear  water,  it  should  be  cleaned.  No  insecticide  nor 
fungicide  should  be  allowed  to  stand  within  the  pump,  but  clear 
water  should  be  pumped  through  it  before  it  is  put  away.  It 
is  well  to  oil  all  the  working  parts  occasionally,  as  a  little  oil  at 
times  may  prevent  the  metal  from  being  cut,  and  the  pump  wrill 
be  thus  preserved  much  longer  than  otherwise.  Nozzles  are  also 
benefited  by  the  same  treatment.  Oil  can  scarcely  be  used  too 
freely  on  the  inside  of  such  apparatus,  and  an  occasional  coat  of 
paint  on  the  outside  will  assist  materially  in  protecting  the 
metal.  The  careless  man  pays  dearly  for  his  neglect. 


CHAPTER  VL 

THE  ACTION  OF  INSECTICIDES  AND  FUNGICIDES. 

SPRAYING  has  become  a  common  practice  with  compar- 
atively few  cultivators.  The  majority  still  waver  when  it 
comes  to  doing  the  work,  hoping  that  they  may  gather  good 
crops  even  if  the  operation  is  not  performed.  Very  few  have 
doubts  of  its  value,  but  for  one  reason  or  another,  at  the 
last  moment  nothing  is  done.  Undoubtedly  much  of  this 
hesitation  is  caused  by  the  uncertainty  whether  as  good 
results  may  be  obtained  by  the  novice  as  are  obtained  by  those 
who  have  had  experience  in  the  work.  I  know  of  a  farmer 
who  owns  a  young  bearing  orchard,  which  almost  every  spring 
has  promised  an  abundant  harvest ;  but  when  fall  came  and  the 
time  for  harvesting  the  crop  drew  near,  the  apples  which  still 
hung  on  the  trees  were  so  full  of  worms  and  so  distorted  by 
fungi  that  the  profits  derived  from  their  sale  were  indeed 
small.  The  man  was  so  impressed  by  the  good  results  of 
spraying  as  practiced  by  one  of  his  neighbors  who  grows  the 
same  varieties  of  apples,  that  in  1894  he  finally  made  prepara- 
tion to  spray  in  earnest.  He  was  advised  as  to  the  best 
methods  of  doing  the  work,  and  the  proper  materials  were 
applied,  yet  at  first  he  could  not  overcome  the  fear  that  his 
trees  would  not  be  just  as  thoroughly  protected  as  others  had 
been,  and  that  in  spite  of  the  application  the  apples  would 
turn  out  as  they  did  in  the  past.  But  the  fruit  was  fair,  and 
his  orchard  will  no  doubt  be  regularly  treated  in  the  future. 

Such  doubts  are  needless.  Protection  by  spraying  will  be 
just  as  efficient  for  one  man  as  for  another,  and  provided  the  ene- 
mies of  the  plants  are  equally  serious,  the  results  in  one  case 
will  be  just  as  marked  as  they  are  in  the  other,  if  a  few  points 
are  observed.  Without  wishing  to  encourage  carelessness  in 
Q  225 


226  The  Spraying  of  Plants. 

this  matter,  it  may  be  said  that  few  of  the  formulas  now  in  use 
will  fail  to  be  effective  even  if  they  are  slightly  modified. 
The  history  of  the  several  formulas  need  only  be  considered 
to  show  that  this  is  the  case.  Spraying  is  not  an  exact 
science,  and  most  of  the  methods  allow  of  considerable  modifi- 
cation. Spray,  by  all  means,  if  the  crops  are  in  need  of  it,  even 
though  the  advice  of  the  experienced  is  not  always  followed  to 
the  letter  in  regard  to  the  best  method  of  making  the  applica- 
tion or  of  preparing  the  materials.  Follow  such  advice  as 
closely  as  possible,  but  no  serious  consequences  will  result  if 
slight  deviations  occur.  Three  points,  however,  cannot  be  too 
strongly  emphasized : 

First,  be  on  time.  Make  an  application  when  it  will  do  the 
most  good,  and  never  allow  that  time  to  pass  if  it  can  possibly 
be  avoided ,  Every  delay  is  of  advantage  to  the  parasite,  and  it 
will  be  used  so  well  that  in  most  cases  the  injury  cannot  be 
repaired.  The  destruction  of  one  insect  may  mean  the  destruc- 
tion of  hundreds,  and  one  application  made  at  the  right  time 
may  mean,  and  generally  does  mean,  the  protection  of  a  plant 
against  millions  of  spores  of  fungi  which  are  endeavoring  to 
gain  a  foothold.  Be  ready  for  action  at  a  moment's  notice, 
and  when  the  moment  comes,  spray  ! 

Second,  be  thorough.  When  spraying  a  plant,  spray  it  well. 
With  a  little  care,  a  complete  success  may  be  obtained  instead 
of  only  a  partial  one.  When  the  work  is  finished,  the  grower 
should  have  the  feeling  that  it  is  well  done,  and  then  no  fear  as 
to  the  result  need  be  entertained.  Spraying  is  not  always 
pleasant  work,  and  the  temptation  to  slight  it  is  often  strong ; 
but  the  operator  will  be  rewarded  just  to  the  extent  to  which 
he  has  been  painstaking,  and  to  that  extent  only. 

Third,  apply  sprays  intelligently.  This  is  really  the  most 
important  factor  in  the  work,  although  good  crops  can  be 
obtained  without  it,  provided  directions  are  followed.  The 
first  two  points  cannot  be  neglected  without  injury  to  the 
crops,  but  this  one  can  be.  The  crop  is  in  need  of  the  applica- 
tions only,  but  the  grower  should  know  the  reasons  for  them, 
and  should  be  in  a  position  to  modify  his  treatments  so  as  to 
make  them  conform  writh  the  character  of  the  insect  or  the 
disease  which  is  being  treated,  and  with  the  season.  Every 
year  and  every  day  such  knowledge  will  be  of  value.  So 


The  Treatment  of  Insects.  227 

many  things  are  still  unknown,  and  so  many  points  still  in  dis- 
pute, that  personal  knowledge  and  judgment  about  individual 
cases  are  not  only  desirable,  but  are  very  essential.  Directions 
covering  the  majority  of  cases  can  be  given,  but  now  and  then 
one  will  come  up  which  seems  to  differ  from  all  others,  and  it 
is  then  that  this  knowledge  will  prove  most  valuable.  A  few 
of  the  general  principles  upon  which  this  work  rests  are  men- 
tioned below. 

The  principal  organisms  against  which  the  cultivator  has  to 
contend  are  insects  and  fungi.  They  are  widely  different  in 
their  organization,  and  entirely  different  substances  are  required 
for  their  destruction.  Any  substance  which  is  used  to  destroy 
or  repel  insects  may  be  termed  an  insecticide ;  and  any  sub- 
stance which  destroys  fungi,  or  which  prevents  their  injurious 
growth  on  vegetation,  is  a  fungicide.  Xo  substance,  so  far  as 
known,  will  answer  both  purposes  equally  well. 

I.    UPON  IXSECTS. 

Practically  all  the  applications  which  are  made  to  destroy  in- 
sects are  designed  to  act  in  one  of  two  ways.  The  substance  may 
be  destined  to  enter  the  digestive  system  of  the  insect  and  thus 
cause  death,  just  as  many  poisons  cause  death  when  taken  into 
the  stomachs  of  higher  animals.  This  method  is  by  far  the 
cheapest,  and  when  possible  it  is  advisable  to  make  use  of  it. 

The  second  method  does  not  consist  in  putting  poison  on 
the  food  of  the  insect,  but  the  material  is  put  directly  upon  the 
insect  itself.  It  then  causes  death  either  by  stopping  up  the 
breathing  pores,  or  it  penetrates  the  outer  coverings  and  so 
enters  the  body  directly.  This  method  cannot  be  used  with 
success  against  all  insects,  as  some  have  very  tough  and  dense 
coverings  which  are  not  readily  penetrated  by  any  material  that 
we  can  use  for  the  purpose.  Beetles,  for  example,  can  scarcely 
be  destroyed  in  this  manner.  But  all  soft-bodied  insects,  such 
as  aphides,  worms,  and  caterpillars,  yield  readily  to  the  treat- 
ment if  sufficient  material  comes  in  contact  with  their  bodies. 

This  method  of  killing  insects  by  means  of  substances  which 
cause  death  merely  by  penetrating  the  creature's  body,  is  rather 
expensive,  and  it  is  resorted  to  only  when  the  pest  cannot  be 
treated  by  poisoning  its  food.  It  thus  comes  that  most  worms 


228  The  Spraying  of  Plants. 

and  caterpillars  are  destroyed  by  means  of  poisons  which  are 
eaten,  though  they  yield  to  the  other  treatment  equally  well. 

The  food  of  many  insects,  however,  cannot  be  poisoned,  since 
they  feed  upon  the  juices  of  plants  and  do  not  eat  the  external 
coverings.  It  is  fortunate  that  most  of  these  insects  have  soft 
bodies,  so  that  they  yield  readily  to  treatment  if  the  poison 
comes  in  contact  with  them.  Their  mouth  parts  are  formed  for 
penetrating  the  external  coverings  of  plants  to  a  depth  suffi- 
cient to  reach  the  sap ;  just  as  the  mosquitoes'  bills  are  in  the 
habit  of  penetrating  human  kind.  All  aphides  belong  to  this 
class,  as  well  as  the  true  bugs,  these  having  mouth  parts  which 
are  adapted  to  suck,  but  not  to  chew.  The  utter  uselessness  of 
covering  a  plant  with  poisons  to  protect  it  from  these  pests 
will  readily  be  seen.  No  matter  how  thick  the  poison  may  be, 
the  insect's  beak  will  penetrate  this  poisonous  layer,  and  it 
will  take  no  food  until  the  beak  has  passed  the  limit  of  the 
poison  and  is  deeply  buried  in  the  tissues  of  the  plant. 

From  the  above  it  will  be  seen  that : 

(a)  To  destroy  chewing  insects,  such  as  the  potato  beetle, 
poisons  must  be  evenly  distributed  over  those  parts  upon  which 
the  insects  feed,  and  this  may  in  some  cases  be  done  even  before 
the  insect  is  present,  or  is  visible.  Only  those  poisons  which 
cause  death  after  being  eaten  should  be  used. 

(ft)  To  destroy  sucking  insects,  such  as  plant  lice,  the  ma- 
terials must  be  distributed  upon  the  insects  as  evenly  as  possi- 
ble, and  it  is  useless  to  make  any  application  before  the  insect 
has  appeared.  Only  those  poisons  which  kill  by  coming  in  con- 
tact with  the  insect's  body  should  be  used. 

First  determine  what  kind  of  a  pest  it  is  that  needs  treat- 
ment, then  select  the  proper  material  from  among  those  men- 
tioned in  Chapter  IV.1 

II.   UPON  FUNGI. 

Among  fungi  we  find  many  serious  enemies.  It  is  difficult  to 
tell  just  what  a  fungus  is,  but  some  of  the  principal  character- 
istics may  be  mentioned.  A  fungus  is  a  plant ;  but  unlike 

1  The  complete  transformations  which  many  insects  undergo  before  maturing 
are  as  follows :  (a)  the  egg ;  (b)  the  larva,  grub,  or  caterpillar ;  (c)  the  pupa  or 
chrysalis ;  (d)  the  imago  or  matured  adult  insect. 


The  Treatment  of  Fungi.  229 

flowering  plants,  it  possesses  no  chlorophyll.  Chlorophyll  is  the 
green-colored  protoplasm  found  in  flowering  plants,  and  it  is  the 
only  substance  we  know  through  which  plants  change  crude  food 
to  nutritive  material.  We  must  conclude,  therefore,  that  fungi 
do  not  prepare  their  own  food,  but  feed  upon  organic  matter 
which  is  already  adapted  to  their  wants.  They  possess  no 
leaves,  flowers,  nor  seeds.  That  part  of  any  fungus  which  is 
of  most  interest  to  the  horticulturist  is  composed  of  long,  fine 
threads,  either  grow  ing  separately  or  in  bundles ;  these  threads 
are  known  as  hyphae,  and  collectively  they  form  the  mycelium 
or  vegetative  portion  of  the  fungus.  The  mycelium  corresponds 
to  the  roots  and  stems  of  flowering  plants. 

Spores,  which  are  organs  performing  the  same  office  as  the 
seeds  of  flowering  plants,  are  produced  by  this  mycelium  either 
directly,  or  upon  branches  (sometimes  called  sporophores)  which 
are  thrown  out.  These  sporophores  cause  the  white  downy 
appearance  seen  upon  grape  leaves  affected  with  the  downy 
mildew.  A  spore,  strictly  speaking,  is  not  a  seed,  for  a  seed 
contains  a  young  plant,  while  a  spore  does  not,  being  usually 
composed  of  only  one  cell.  If  a  spore  finds  the  proper  condi- 
tions of  heat  and  moisture  it  will  germinate  and  send  out  a 
fine  filament,  which,  if  nourished,  grows  and  branches,  and 
eventually  a  plant  like  the  original  will  be  produced. 

Most  fungi  in  the  North  produce  two  kinds  of  spores,  known 
as  the  summer  and  the  winter  spores.  The  summer  spores  are 
usually  borne  upon  the  exterior  of  the  host-plant,  or  the  plant 
on  which  the  fungus  grows.  These  spores  ripen  quickly  and 
propagate  the  fungus  rapidly.  But  if  they  do  not  germinate 
soon  after  ripening  they  lose  their  vitality. 

The  winter  spores  are  usually  produced  within  the  tissues  of 
the  host-plant,  commonly  in  the  leaves  and  fruit.  They  are 
the  spores  which  live  through  the  winter;  but  in  the  spring, 
under  favorable  circumstances,  they  germinate,  and  thus  the 
fungus  is  again  developed. 

Fungi  may  be  divided  into  two  general  classes :  those  grow- 
ing upon  dead  and  decaying  matter,  or  saprophytes ;  those  feed- 
ing upon  living  tissue,  or  parasites.  By  far  the  larger  portion 
possessing  interest  to  the  horticulturist  belong  to  the  latter 
class,  for  in  this  are  included  the  fungi  which  do  so  much 
injury  to  cultivated  plants. 


230  The  Spraying  of  Plants. 

Yet  all  parasitic  fungi  do  not  attack  the  host-plant  in  the 
same  manner.  Some  immediately  penetrate  into  the  interior 
tissues,  and  there  they  flourish,  being  well  protected  from  outer 
influences  by  the  exterior  covering  of  the  plant.  The  fungi 
causing  all  the  more  serious  diseases  develop  in  this  manner, 
and  in  fact  the  vast  majority  of  plant  diseases  are  caused  by 
such  organisms.  There  are  others,  however,  in  which  the 
body  of  the  fungus  is  almost  entirely  upon  the  surface  of  the 
host-plant,  only  a  comparatively  small  number  of  threads  pene- 
trating the  tissues  in  order  to  obtain  nourishment.  These 
parasites  can  be  rubbed  off,  and  unless  the  attack  has  been 
very  severe,  the  green,  healthy  tissue  will  be  seen  underneath. 
This  class  may  for  convenience  be  termed  "surface  fungi,"  to 
distinguish  them  from  those  which  grow  within  the  host-plant ; 
it  is  represented  by  the  common  powdery  mildew  of  the  grape, 
one  mildew  of  the  gooseberry,  one  of  the  strawberry,  and  a  few 
others. 

The  life  histories  of  the  various  fungi  must  form  the  basis 
for  any  methods  of  treatment  which  may  be  adopted.  During 
certain  stages  of  their  existence,  parasitic  fungi  may  be  checked 
quite  easily,  and  at  such  times  the  remedies  should  be  applied. 

It  is  evident  that  when  a  fungus  has  once  become  established 
inside  the  host-plant,  it  cannot  be  reached  without  destroying  the 
tissues  of  the  host  in  the  affected  places,  which  is  by  no  means 
desirable.  The  fungus  must  be  destroyed  before  it  enters  the 
host ;  in  other  words,  the  spores  must  be  killed  as  soon  as  they 
germinate,  or  better,  they  must  not  be  allowed  to  germinate. 
All  applications  must  be  preventive,  not  curative,  since  a  cure 
is  practically  impossible  when  the  fungus  is  once  established, 
unless  it  grows  upon  the  surface  of  the  host. 

The  line  of  treatment  indicated  is  this :  to  cover  the  stems 
and  foliage  of  the  cultivated  plant  with  some  substance  that 
will  destroy  the  spores  which  may  be  present,  as  soon  as  they 
germinate,  or  with  one  that  will  have  the  power  of  prevent- 
ing this  germination.  If  that  is  done,  the  plant  will  remain 
healthy,  so  far  as  fungi  are  concerned ;  otherwise  it  will  not, 
unless,  indeed,  no  fungus  attacks  it.  Several  substances  which 
destroy  these  spores,  as  well  as  the  surface  fungi,  have  already 
been  found.  They  are  easily  applied,  safe,  and  effective,  and 
any  grower  who  suffers  his  fruit  to  be  ruined  by  these  para- 


The  Effect  upon  the  Host-Plant.  231 

sites  is,  as  a  rule,  deserving  of  his  loss,  for  means  of  destroying 
the  pests  are  at  his  command.  It  is  largely  the  grower's  fault  if 
his  apples  are  scabby,  if  his  grapes  are  mildewed,  and  if  his 
potatoes  rot  in  the  field.  Spraying  is  no  longer  an  experiment, 
it  is  a  necessity;  and  those  who  recognize  this  fact  are  the 
ones  who  are  reaping  the  rewards. 

III.   UPON  THE  HOST-PLANT. 

Insecticides  and  fungicides  are  applied  solely  for  their  action 
upon  the  organisms  it  is  desired  to  destroy,  since  in  other  respects 
most  of  the  preparations  possess  no  value.  If  properly  applied 
they  are  harmless  to  the  plants,  and  should  not  in  any  way 
interfere  with  their  proper  growth  nor  with  the  sale  of  the 
products.  When  some  of  the  mineral  preparations,  however, 
are  too  freely  used  late  in  the  season,  the  appearance  of  the 
crop  may  reduce  to  a  considerable  extent  its  market  value, 
although  the  product  may  be  still  as  wholesome  as  if  untreated. 

Fears  have  also  been  entertained  that  some  substances  are 
dangerous  even  when  not  visible,  on  account  of  their  effect 
upon  the  crop,  which  was  supposed  to  be  poisoned.  This  sub- 
ject was  well  agitated  when  Paris  green  and  London  purple 
began  to  be  commonly  used  in  the  destruction  of  the  potato 
beetle.  Many  analyses  were  made,  but  no  arsenic  could  be 
found,  either  in  the  tubers  or  in  the  parts  above  ground,  and 
soon  all  fear  of  arsenical  poisoning  disappeared,  and  potatoes 
treated  with  the  arsenites  were  used  without  question.  Another 
equally  groundless  objection  was  raised  in  England  regarding 
American  apples  which  had  been  sprayed  for  the  canker-worm 
or  codlin-moth.  It  was  said  that  the  bloom  found  on  American 
apples  consisted  largely  of  the  arsenic  which  had  been  applied 
to  the  trees  to  destroy  insects,  and  that  such  apples  were  unfit 
for  use.  These  reports  have  led  to  many  chemical  examina- 
tions of  sprayed  fruit,  and  only  in  rare  cases  has  even  a  trace  of 
arsenic  been  found.  It  is  only  when  very  late  applications  are 
made,  such  as  are  utterly  useless,  that  any  of  the  poison  is  found 
upon  the  fruit,  and  then  the  quantities  are  so  minute  that  they 
could  in  no  way  cause  injury  to  the  consumer.  But  even  though 
all  the  poison  sprayed  upon  the  apples  in  making  necessary 
treatments  should  remain  there  undisturbed,  a  person  would  be 


232  The  Spraying  of  Plants. 

obliged  to  eat  at  one  meal  eight  or  ten  barrels  of  the  fruit  in 
order  to  consume  enough  arsenic  to  cause  any  injury.  As  a 
matter  of  fact,  however,  the  poison  all  disappears  during  the 
growth  of  the  apples,  and  these  are  as  wholesome  as  if  no 
treatment  had  been  made,  or  even  more  so. 

Similar  objections  have  also  been  raised  in  the  case  of  grapes 
sprayed  with  the  Bordeaux  mixture.  In  the  fall  of  1891,  the 
board  of  health  of  New  York  city  seized  considerable  quantities 
of  grapes  which  showed  the  presence  of  Bordeaux  mixture,  and 
threw  them  into  the  river.  The  following  report  of  the  board 
appeared  after  an  investigation  had  been  made  : 

"  1.  A  copper  salt  is  found  only  upon  a  very  small  part  of  the 
grapes  offered  for  sale,  and  the  grapes  which  are  to  be  avoided 
are  easily  recognized  by  the  greenish-colored  substance  upon 
the  berries  and  stems. 

U2.  Whenever  the  substance  is  apparent  upon  the  berries  or 
stems,  the  grapes  should  be  washed  before  they  are  used  as 
food  or  in  the  manufacture  of  wine. 

•  "  3.  The  board  urges  all  dealers  and  consignors  in  this  city 
to  advise  shippers  and  consignors  of  grapes  to  send  no  more 
grapes  to  the  market  upon  which  this  substance  is  apparent. 
The  board  further  states  that  it  does  not  object  to  the  use  of 
Bordeaux  mixture  as  recommended  by  the  proper  authorities; 
but  such  mixture,  or  any  mixture  containing  poisonous  sub- 
stances, should  not  be  sprayed  or  otherwise  placed  upon  the  grapes 
immediately  before  or  after  they  have  matured,  arid  should  not 
appear  upon  them  when  sent  to  market  or  offered  for  sale." 

This  subject  is  equally  interesting  from  a  hygienic  stand- 
point, for  whether  grapes  are  sold  in  the  open  market  or  not, 
their  effect  upon  the  consumer  should  be  understood.  The 
following  paragraph  is  a  clear  and  concise  statement  of  the 
facts  bearing  upon  the  question  : *  "  Accepting,  then,  0.5  gram 
as  the  maximum  amount  of  copper  in  any  of  the  forms  dis- 
cussed that  may  with  safety  be  daily  absorbed,  let  us  see  how 
these  figures  compare  with  the  quantity  of  this  metal  found 
in  connection  with  properly  sprayed  fruits,  as  well  as  some 
other  foods  and  drinks.  Analyses  to  determine  the  amount 
of  copper  in  sprayed  grapes  have  been  made  in  Germany, 
France,  America,  and  other  countries.  The  results  of  all  these 

1  U.  S.  Dept.  Agric.  Farmers'  JButtetin  No.  7, 19. 


The  Effect  upon  the  Host-Plant.  233 

show  that  grapes  sprayed  intelligently  rarely  contain  more 
than  5  milligrams  (0.005  gram)  of  copper  per  kilogram,  the 
average  being  from  2|-  to  3  milligrams  per  kilogram.  In 
other  words,  1,000,000  pounds  of  grapes  sprayed  in  the  usual 
way  with  the  Bordeaux  mixture  would  contain  from  2|  to  5 
pounds  of  copper.  To  reduce  the  figures  still  further,  each 
1000  pounds  of  fruit  would  contain  17.5  to  35  grains  of  copper. 
On  this  basis  an  adult  may  eat  from  300  to  500  pounds  of 
sprayed  grapes  per  day  without  fear  of  ill  effects  from  the 
copper.  This  shows  how  ridiculously  absurd  are  the  state- 
ments that  fruits  properly  sprayed  with  the  Bordeaux  mixture 
or  any  other  copper  compound  are  poisonous." 

The  effect  of  applying  soluble  arsenic  upon  foliage  has  been 
considered  on  page  117,  but  there  still  remains  a  point  in  regard 
to  the  injury  done  by  arsenical  poisons  to  animals  consuming 
the  grass  beneath.  Professor  Cook  has  carefully  experimented 
in  this  direction,  and  his  results  are  so  conclusive  that  they  are 
here  given  in  full :  "  In  tree  No.  1  a  thick  paper  was  placed 
under  one-half  of  a  rather  small  apple  tree.  The  space  covered 
was  six  by  twelve  feet,  or  seventy-two  square  feet.  The  paper 
was  left  till  all  dripping  ceased.  As  the  day  was  quite  windy, 
the  dripping  was  rather  excessive.  In  this  case  every  particle 
of  the  poison  that  fell  from  the  tree  was  caught  on  the  paper. 
Dr.  R.  C.  Kedzie  analyzed  the  poison  and  found  four-tenths  (.4) 
of  a  grain  [of  arsenic].  Tree  No.  2  was  a  large  tree  with  very 
thick  foliage.  Underneath  this  tree  was  a  thick  carpet  of 
clover,  blue  grass,  and  timothy  just  in  bloom.  The  space  cov- 
ered by  the  tree  was  fully  sixteen  feet  square,  or  equal  to  two 
hundred  and  fifty-six  square  feet.  As  soon  as  all  dripping  had 
ceased,  the  grass  under  the  tree  was  all  cut  very  gently  and 
very  close  to  the  ground.  This  was  taken  to  the  chemical 
laboratory  and  analyzed  by  Dr.  R.  C.  Kedzie.  There  were 
found  2.2  grains  of  arsenic.  Now,  as  our  authorities  say  that 
one  grain  is  a  poisonous  dose  for  a  dog,  two  for  a  man,  ten  for 
a  cow,  and  twenty  for  a  horse,  there  would  seem  to  be  small 
danger  from  pasturing  our  orchards  during  and  immediately 
after  spraying,  especially  as  no  animal  would  eat  the  sprayed 
grass  exclusively.  To  test  this  fully,  I  sprayed  a  large  tree 
over  some  bright,  tender  grass  and  clover.  I  then  cut  the 
clover  carefully,  close  to  the  ground,  and  fed  it  all  to  my  horse. 


234  The  Spraying  of  Plants. 

It  was  all  eaten  up  in  an  hour  or  two,  and  the  horse  showed  no 
signs  of  injury.  This  mixture,  remember,  was  of  double  the 
proper  strength,  was  applied  very  thoroughly,  and  all  the  grass 
fed  to  and  eaten  by  the  horse.  This  experiment  was  repeated 
with  the  same  result.  I  next  secured  three  sheep.  These  were 
kept  till  hungry,  then  put  into  a  pen  about  a  tree  under  which 
was  rich,  juicy,  June  grass  and  clover.  The  sheep  soon  ate  the 
grass,  yet  showed  no  signs  of  any  injury.  This  experiment  was 
repeated  twice  with  the  same  result.  It  seems  to  me  that  these 
experiments  are  crucial,  and  settle  the  matter  fully.  The  analy- 
ses show  that  there  is  no  danger,  the  experiments  confirm  the 
conclusion. 

"  Thus  we  have  it  demonstrated  that  the  arsenites  are  effec- 
tive against  the  codlin-moth,  that  in  their  use  there  is  no  danger 
of  poisoning  the  fruit,  and  when  used  properly  no  danger  to  the 
foliage  nor  to  stock  that  may  be  pastured  in  the  orchard."1 

The  danger  following  the  use  of  copper  compounds  on  foliage 
is  naturally  even  less  than  when  a  form  of  arsenic  is  applied. 
One  case  is  on  record  in  which  poisoning  has  followed  when 
grape  foliage  was  eaten  by  sheep,  this  having  been  sprayed 
with  the  Bordeaux  mixture.2  Since  sprayed  foliage  is  probably 
never  fed  regularly  to  stock,  there  need  be  no  cause  of  appre- 
hension in  this  respect. 

The  extent  to  which  copper  is  absorbed  by  foliage  still 
remains  an  open  question.  The  researches  of  Millardet  and 
Gayon  show  that  a  certain  amount  of  copper  is  absorbed  and 
retained  by  the  cuticle  of  the  leaf.3  The  investigations  of 
Rumm,  however,  show  that  such  is  not  the  case.4  If  the 
copper  is  actually  absorbed  the  quantities  are  exceedingly 
minute.  That  it  possesses  a  stimulating  action  upon  foliage 
is  also  doubtful.  Lime  may  have  such  an  effect,  since  several 
cases  are  on  record  in  which  the  application  of  Bordeaux  mix- 
ture produced  a  greener  appearance  of  the  healthy  foliage. 

1  A.  J.  Cook,  Ann.  Kept.  Mich.  Bd.  Agric.  1889,  820. 

2  Wiener  Landw.  Ztg.  1892,  494. 

3  Jour.  d?Ag.  Prat.  18ST,  Jan.  27,  123,  and  Feb.  3,  156. 

*  "Ueber  die  Wirkung  der  Kupferpraparate  bei  Bekampfung  der  sogenannten 
Blattfallkrankheit  der  Weinrebe."  Ber.  d.  Deut.  Bot.  Ges.  Bd.  11,  Heft  2,  1893, 
79-S3;  Ibid.  Heft  7,  445-452.  See,  also,  adverse  critical  review  by  Zimmermann 
in  Bot.  Centralbl.  1893,  No.  23,  308;  Nos.  29,  30,  119,  120;  and  Aderbold  in  Bot. 
Zeit.  No.  11, 1893,  162.  Cited  by  Fairchild  in  Bull.  6,  Sec.  Veg.  Path.  U.  S.  Dept 
Agric.  27. 


The  Effect  upon  the  Soil.  235 

The  benefits  derived  have  not  yet  been  fully  determined.  It 
has  been  estimated  that  the  germination  of  spores  of  certain 
fungi  may  be  prevented  by  solutions  of  lime  containing  1  part 
to  10,000  of  the  liquid ;  or  iron  sulphate,  1  part  to  100,000  of 
water  ;  or  copper  sulphate,  1  part  to  10.000,000  of  water.1  This 
readily  explains  the  energetic  action  of  the  copper  compounds, 
and  why  such  small  amounts  may  be  applied  to  advantage. 

For  further  information  concerning  the  action  of  copper 
compounds  when  applied  to  plants,  consult  R.  Otto,  "Unter- 
suchungen  iiber  das  Verhalten  der  Pnanzenwurzeln  gegen  Kup- 
fersalzlosungen"  (Zeitschrift  fur  PJlanzenkrankheiten,  Bd.  iii. 
1893,  Heft  6).  The  plants  studied  in  these  investigations 
were  Phaseolus  vulgaris,  Zea  Mays,  Pisum  sativum.  It  was 
found  that  "copper  exercises  a  poisonous  influence  upon  the 
plants,  it  interferes  with  the  development  of  the  roots  and 
lessens  the  activity  of  the  functions  of  the  plant,  or  kills  the 
latter  outright,  when  the  roots  of  the  plants  are  growing  in 
more  or  less  concentrated  solutions  of  copper  sulphate."  It  was 
also  found  that  practically  no  copper  was  absorbed  by  the  roots, 
and  the  parts  above  ground  were  entirely  free  from  the  metal. 
See  review  in  Botanisches  Centralblatt,  1893,  Vol.  55,  340-342. 

See  also,  A.  Tschirch,  "Das  Kupfer  vom  Standpunkte  der  ge- 
richtlichen  Chemie,  Toxicologie,  und  Hygiene.  Mit  besonderer 
Beriicksichtigung  der  Reverdissage  der  Conserven  und  der 
Kupferung  des  Weins  und  der  Kartoffeln."  Stuttgart  (F.  Enke), 
1893.  The  entire  question  of  the  use  of  copper  compounds 
upon  cultivated  plants  is  thoroughly  discussed  by  the  author. 
In  general  his  conclusion  is,  "to  remove  all  copper. from  articles 
of  diet  means  forbidding  the  plant  to  absorb  it  from  the  soil, 
and  also  considering  as  injurious  to  health  the  use  of  bread  and 
chocolate."  See  Botanisches  Centralblatt,  1893,  Vol.  55,  170-175, 
for  a  detailed  review  of  the  work. 


IV.   UPON  THE  SOIL. 

Doubts  have  been  very  frequently  expressed  as  to  the  final 
outcome  of  the  continual  addition  of  insecticides  and  fungicides 
to  the  soil,  it  being  supposed  that  the  roots  of  the  plants  as 
well  as  the  soil  itself  would  eventually  suffer.  Scientific  inves- 

i  Millardet  et  Gayon,  Jour.  &Ag.  Prat.  1885,  Nov.  12,  707. 


236  The  Spraying  of  Plants. 

tigation  has  shown  these  fears  to  be  groundless,  as  it  has  so 
many  other  doubts  formerly  entertained.  The  following  ex- 
tracts should  prove  sufficiently  convincing  even  to  the  most 
skeptical :  x 

"  Former  analyses  of  unsprayed  top  soils  of  the  station  farm 
have  shown  no  trace  of  copper  in  their  composition.  Recent 
analyses  of  top  soils  taken  from  an  old  potato  field  which  has 
received  many  applications  of  Paris  green  (an  aceto-arsenite  of 
copper),  show  from  three  ten-thousandths  to  three  and  one-third 
ten-thousandths  of  one  per  cent  of  metallic  copper.  Analyses  of 
top  soils  from  a  portion  of  the  same  field  to  which  Bordeaux 
mixture  was  applied  last  season  for  the  potato  blight  show 
four  ten-thousandths  of  one  per  cent  of  metallic  copper,  equal 
to  about  sixteen  ten-thousandths  of  one  per  cent  in  the  form  of 
copper  sulphate.  English  writers  frequently  speak  of  using 
from  22  to  32  pounds  of  copper  sulphate  per  acre  in  one  season's 
application  of  Bordeaux  mixture  for  potato  blight.  To  impreg- 
nate such  soil  as  that  which  was  used  in  the  above  analysis  to 
the  depth  of  one  foot  with  one  per  cent  of  copper  sulphate  would 
require  about  32,625  pounds  of  the  sulphate,  which,  if  applied 
at  the  rate  of  30  pounds  a  year,  would  require  in  its  application 
nearly  1100  years,  provided  that  none  of  it  escaped  in  drainage." 

Some  experiments  conducted  by  Bailey  in  1895  indicate  that 
practically  no  danger  is  to  be  feared  from  very  heavy  applica- 
tions of  arsenites  to  soil.  His  conclusion  is  as  follows :  "  The 
arsenic  which  falls  upon  the  soil  seems  to  become  or  to  remain 
in  an  insoluble  condition,  and  passes  downward,  if  at  all,  to  a 
very  little  distance,  and  then  only  by  the  mechanical  action  of 
water  in  carrying  it  through  spaces  in  the  soil."2 

The  results  obtained  by  a  careful  European  investigation8 
are  also  inserted  here,  that  the  subject  may  be  viewed  from 
different  standpoints.  The  only  conclusion  to  be  drawn  from 
these  extracts  is  that  proper  applications  of  insecticides  and 
fungicides  will  apparently  never  cause  any  appreciable  injury 
either  to  the  roots  of  plants  or  to  the  soil : 

"  1.   Soluble  copper  salts  are  injurious  to  plants ;  the  injurious 

1  Beach,  Country  Gentleman,  1892,  68. 

2  Cornell  Agric.  Exp.  Sta.  1895,  Bull.  101,  502. 

3Haselhoff,  "Injurious  action  of  solutions  of  the  sulphate  and  the  nitrate  of 
copper  upon  soil  and  plants,"  Landwirthschaftliche  Jdhrbucher,  1892,  272-276. 


The  Effect  upon  the  Crop.  237 

action  begins  when  10  milligrams  of  copper  oxide  are  present  in 
1  liter  of  water,  but  when  only  5  milligrams  per  liter  are  present 
no  marked  effects  can  be  seen. 

"  2.  If  solutions  of  copper  sulphate  and  of  copper  nitrate  are 
applied  to  soils,  the  plant  food  present,  especially  lime  and 
potash,  are  dissolved  and  washed  away;  the  copper  oxide  is 
absorbed  by  the  soil.  As  a  result  of  these  two  processes,  the 
fertility  of  the  soil  is  more  or  less  decreased. 

"  3.  Barley  and  oats  suffer  more  than  grass  from  solutions  of 
copper  sulphate  and  copper  nitrate;  copper  sulphate  is  more 
injurious  to  corn  than  to  beans. 

"4.  The  injurious  action  of  copper  sulphate  and  copper 
nitrate  is  counteracted  if  an  excess  of  the  carbonate  of  lime  is 
present  in  the  soil.  But  as  soon  as  this  excess  has  been  acted 
upon,  the  injurious  processes  take  place  in  the  same  manner  as 
in  soils  in  which  no  lime  is  found." 

V.  UPON  THE  VALUE  OF  THE  CHOP. 

It  is  scarcely  necessary  to  enter  into  details  regarding  the 
benefits  derived  from  proper  applications  of  insecticides  and 
fungicides.  Experiment  stations  and  private  growers  have 
many  times  demonstrated  that  the  market  value  of  the  product 
is  increased  to  such  an  extent  that  the  cost  of  materials  and  of 
labor  is  returned  many-fold  to  the  grower,  whenever  proper 
applications  have  been  made.  Indeed,  the  conditions  now  are 
such  that  it  is  as  necessary  to  spray  certain  crops  as  it  is  to  cul- 
tivate them.  Doubts  are  no  longer  entertained  concerning  the 
treatment  of  potatoes  with  arsenites ;  the  operation  is  generally 
performed  as  one  of  the  regular  duties  in  obtaining  a  crop.  The 
majority  of  the  best  apple  growers  have  come  to  feel  the  same 
concerning  apples.  They  spray  with  insecticides  for  the  codlin- 
moth  and  other  insects,  and  with  the  Bordeaux  mixture  for 
fungous  diseases.  The  operations  have  passed  the  stage  of 
experiment,  and  are  now  considered  in  the  light  of  a  necessity. 

The  grape  is  another  striking  illustration  of  the  same  truth. 
In  many  sections,  especially  in  the  southern  states,  it  is  practi- 
cally impossible  to  obtain  a  sound  crop  on  account  of  the  abun- 
dance of  fungous  diseases.  There  it  is  not  only  a  question  of 
profits,  for  it  is  difficult  to  obtain  any  crop  whatever.  Peaches, 


238  The  Spraying  of  Plants. 

plums,  cherries,  quinces,  all  the  small  fruits,  and  many  vegeta- 
bles, will  generally  repay  proper  treatment. 

A  secondary  benefit  is  also  derived  in  those  products  which 
are  stored.  Unsound  fruit  will  not  keep,  for  decay  generally 
begins  in  a  part  which  has  already  been  injured.  It  has  been 
said  that  sprayed  fruit  will  keep  longer  than  that  wrhich  has  not 
been  treated,  even  though  both  are  free  from  blemishes.  The 
question  is  open  to  doubt,  however,  since  no  decisive  experiments 
have  yet  been  made.  But  the  more  nearly  perfect  the  stored  crop 
is  when  put  in,  the  longer  it  will  keep  and  the  greater  value  it 
will  possess,  other  conditions  being  equal. 

It  must  not  be  inferred  from  the  preceding  remarks  that  all 
crops  should  be  sprayed.  The  question  "  Does  spraying  pay  ?  " 
can  best  be  answered  by  the  grower,  and  he  must  be  his  own 
judge  regarding  the  advisability  of  treatments.  Let  the  question 
be  considered  from  the  proper  standpoint  and  the  matter  will  be 
simplified.  The  final  test  in  regard  to  the  making  of  treatments 
may  be  stated  in  this  form :  does  the  difference  between  the  mar- 
ket value  of  sound  fruit,  and  the  value  of  the  product  obtained 
when  no  treatments  are  made,  warrant  the  expense  of  purchas- 
ing materials  and  the  labor  of  making  the  applications?  The 
grower  knows  the  price  received  for  his  crop ;  he  also  knows  the 
price  paid  for  perfect  or  fancy  crops ;  the  difference  between 
the  two,  so  far  as  injuries  from  insects  and  fungi  are  concerned, 
shows  to  what  extent  the  crop  may  be  benefited  by  treatments. 
It  is  then  a  simple  matter  to  determine  if  the  applications  will 
pay.  It  will  be  noted  that  little  question  regarding  the  efficiency 
of  the  applications  is  here  entertained.  It  is  taken  for  granted, 
and  with  good  reason,  that  proper  treatment  must  produce  the 
desired  result.  The  arsenites  will  destroy  all  chewing  insects, 
with  scarcely  an  exception,  and  the  copper  compounds  will  pre- 
vent injury  from  most  fungi;  these  are  established  facts,  but 
it  remains  for  the  grower  to  apply  them.  There  probably 
exists  an  economical  remedy  for  every  disease  of  plants ;  the 
vast  majority  of  these  diseases  are  now  under  control,  and 
although  a  few  obstinate  cases  still  exist,  the  future  is  encourag- 
ing when  we  consider  the  progress  made  in  the  past.  Intelli- 
gence, knowledge,  and  good  judgment,  when  assisted  by  in- 
secticides and  fungicides,  will  prove  more  than  a  match  for 
these  organisms  which  prey  upon  the  products  of  man's  labors. 


PART  II. 

SPECIFIC  DIRECTIONS  FOR   SPRAYING 
CULTIVATED  PLANTS. 


ALMOND. 

FUNGOUS  DISEASES. 

Leaf  Blight;  Almond  Disease  (Cercospora  circumcissa,  Sacc.). 
—  Description.  This  disease  is  especially  serious  in  California, 
the  trees  often  being  practically  defoliated  during  the  summer. 
The  fungus  attacks  the  leaves  and  the  stems.  Upon  the 
former  it  produces  small  circular  spots,  the  diseased  areas 
being  more  or  less  restricted  by  the  small  veins  of  the  leaves. 
The  spots  are  about  an  eighth  of  an  inch  in  diameter,  and 
upon  the  death  of  the  tissue  the  discolored  areas  fall  from  the 
leaves,  causing  an  appearance  similar  to  that  of  the  shot-hole 
fungus  upon  plum  foliage.  Diseased  stems  also  show  distinct 
spots  of  circular  or  oval  outline.  The  dead  tissue  soon  falls 
out,  producing  a  pitted  appearance  on  the  surface  of  the  af- 
fected twigs. 

Treatment.  N".  B.  Pierce,  who  has  thoroughly  studied  this 
disease,  recommends  spraying  the  trees  with  the  ammoniacal 
carbonate  of  copper,  making  the  first  application  before  the 
trees  bloom,  the  second  when  the  trees  are  in  full  leaf,  and 
the  third  four  weeks  later.1 

1  Galloway,  Ann.  Hep.  U.  S.  Com.  of  Agrie.  1892,  232. 
239 


240 


The  Spraying  of  Plants. 


APPLE. 


FUNGOUS  DISEASES. 


Bitter  Rot;  Ripe  Rot  (Glceosporium  fructigenwn,  Berk.  G. 
versicolor  ?) .  —  Description.  Apples  are  often  seriously  injured, 
especially  in  some  of  the  southern  states,  by  a  rot  which  causes 


FIG.  37.  — The  bitter-rot  of  apples. 

a  softening  of  the  tissues  of  the  fruit,  and  changes  them  from 
their  normal  color  to  a  brown  (Fig.  37).  This  rot  "  takes  fruit 
at  any  stage  of  its  growth  from  the  time  it  is  about  three- 
quarters  of  an  inch  in  diameter  until  it  is  ripe."1  It  is  by 

i  Garman,  Ky.  Agric.  Exp.  Sta.  1893,  Bull.  44,  4. 


Apple.  241 

no  means  uncommon  in  the  northern  states,  and  appears  to 
be  particularly  destructive  to  the  earlier  varieties.  Early 
Harvest,  Sweet  Bough,  and  others  are  very  subject  to  the  dis- 
ease. Any  part  of  the  apple  may  be  first  attacked,  and  when 
the  fungus  has  once  gained  a  foothold  it  spreads  very  rapidly. 
The  older  portion,  or  the  part  first  attacked,  soon  bears  small 
black  pimples,  and  it  is  said  that  the  tissue  beneath  them  has 
an  exceedingly  bitter  taste,  which  has  given  the  disease  its 
name. 

Treatment.  Carman1  recommends  the  use  of  Bordeaux  mix- 
ture for  preventing  the  development  of  the  disease.  He  obtained 
the  greatest  benefit  from  applications  made  as  follows :  First, 
before  the  leaves  expanded;  second,  soon  after  the  apples  had 
set ;  third,  about  fourteen  days  later ;  fourth,  four  weeks  after 
the  preceding.  In  this  manner  "  thirty-one  and  one-sixth  per 
cent  of  the  whole  number  of  apples  borne  by  the  sprayed  tree 
during  the  season  were  saved  from  the  rot." 

The  disease  has  also  been  successfully  treated  by  the  use  of 
the  sulphide  of  potassium.  The  ammoiriacal  carbonate  of 
copper  gave  similar  results.  These  last  experiments  are  inter- 
esting from  the  fact  that  the  first  application  was  not  made  till 
about  the  middle  of  August.  Earlier  applications  are,  however, 
advisable. 

Black  Rot  (Sphceropsis  malorum,  Berk.).  —  Description.  The 
external  characters  of  this  disease  are  practically  identical  with 
those  of  the  Bitter  Rot.  The  remedies  to  be  used  are  also  the 
same. 

Brown  Rot.     See  under  CHERRY. 

Powdery  Mildew  (Podosphcera  Oxycanthce,  DeBary).  —  Descrip- 
tion. This  fungus  attacks  the  foliage  of  young  apple  seedlings 
very  soon  after  the  unfolding  of  the  leaves,  and  continues 
its  growth  throughout  the  summer,  very  much  weakening  the 
plants,  and  making  them  unfit  for  budding  purposes.  The  dis- 
ease is  especially  serious  in  the  southern  states.  The  affected 
leaves  have  a  grayish  appearance  which  is  caused  by  a  powdery 
substance.  This  gray  powder  consists  of  the  parts  of  the  fungus 
which  project  beyond  the  leaf  tissue.  The  leaf  soon  dries  and 
is  rendered  worthless. 

Treatment.     The  trouble  has  been  successfully  controlled  by 

1  Gorman,  Ky,  Agric.  Exp.  Sta.  1893,  Bull.  44,  5. 
E 


242  The  Spraying  of  Plants. 

the  Section  of  Vegetable  Pathology  at  Washington,  and  the 
following  are  the  conclusions  reached  :  * 

"  1.  The  disease  can  be  effectually  prevented  by  the  applica- 
tion of  the  ammoniacal  solution  of  carbonate  of  copper. 

"  2.  In  the  nursery  the  total  cost  of  the  treatment  need  not 
exceed  twelve  cents  per  1000  trees. 

"  3.  The  first  application  should  be  made  when  the  leaves  are 
about  one-third  grown,  and  should  be  followed  by  at  least  five 
others  at  intervals  of  ten  or  twelve  days." 

Rust  (Rcestelia  pirata,  Thax.,  and  Gymnosporangium  macropm, 
Link.).  —  Description.  The  fungus  which  causes  the  rust  of 
apples  is  one  of  the  most  peculiar  in  which  the  horticulturist 
is  interested.  Unlike  many  fungi,  this  one  lives  upon  two  host- 
plants  during  its  course  of  development.  These  host-plants  are 
the  apple,  and  the  cedar  or  juniper.  There  are  probably  several 
species  of  rusts  which  attack  cultivated  apples,2  but  the  histories 
of  all  are  essentially  the  same.  The  most  common  one  is  now 
supposed  to  be  Roestalia  pirata,  Thax.3 

The  effects  of  this  fungus  upon  the  apple  are  first  noticeable 
during  the  latter  part  of  May,  or  in  early  June.  The  leaves  are 
then  dotted  with  bright  yellow  spots,  the  so-called  rust;  the 
fruit  is  also  attacked  about  the  same  time.  Such  fruit  becomes 
worthless,  as  the  growth  is  increased  at  the  diseased  point,  and 
the  swollen  part  produces  spores,  which  ruins  the  apples.  Spores 
are  also  produced  upon  the  under  side  of  the  leaves.  They  ap- 
pear and  ripen  during  midsummer.  They  will  not  germinate 
and  grow  upon  either  the  leaves  or  fruit  of  the  apple,  but  they 
will  develop  the  fungus  upon  the  cedar.  There  the  mycelium 
enters  the  tissues,  and  as  growth  advances,  enlargements  appear 
upon  the  branches  of  the  tree.  Such  swellings,  or  "  cedar-apples," 
as  they  are  called,  are  from  half  an  inch  to  almost  two  inches  in 
diameter;  they  become  full  grown  early  in  spring.  During 
April  and  May,  horn-shaped  masses  an  inch  or  more  in  length 
are  produced  by  the  cedar-apple.  They  are  of  a  bright  yellow 
color  and  can  readily  be  seen  among  the  green  branches  of  the 
cedars.  Upon  these  soft,  yellow  bodies  the  spores  are  borne; 
these  spores  will  not  grow  upon  cedars,  but  only  upon  the  leaves 

1  Ann.  Rep.  V.  S.  Com.  Agrie.  1889,  415. 

2  Byron  D.  Halsted,  Ann.  Rep.  U.  S.  Com.  Agrie.  1888,  3T6. 

3  Scribner,  "  Fungous  Diseases  of  the  Grape  and  other  Plants,"  1890,  84. 


Apple.  243 

or  fruit  of  the  apple.  They  ripen  in  spring,  and  consequently  it 
is  at  this  season  of  the  year  that  the  apple  trees  must  be  pro- 
tected. Unfortunately,  when  a  tree  has  once  become  infected, 
it  seems  that  the  mycelium  of  the  rust  may  remain  in  the  buds 
and  branches  for  years,  and  in  the  spring  when  the  young  leaves 
have  formed,  the  characteristic  yellow  spots  may  again  appear, 
although  no  new  infection  has  taken  place.,  The  disease  is 
sometimes  so  serious  that  the  tree  loses  all  its  foliage,  and  this 
alone  would  ruin  the  crop,  although  the  apples  themselves  may 
not  be  attacked. 

Treatment.  It  is  difficult  to  combat  the  apple  rust  successfully. 
Since  apple  trees  are  attacked  by  spores  which  are  produced  upon 
cedar  trees,  it  naturally  follows  that  by  removing  all  cedars  we 
also  remove  the  source  of  the  disease.  Cutting  and  burning 
the  cedar-apples  before  the  appearance  of  the  yellow  horns  will 
answer  the  same  purpose.  In  many  cases,  however,  such  a 
course  is  impracticable  on  account  of  the  abundance  of  the 
trees.  Scribner  advises l  the  removal  of  all  badly  diseased  trees 
in  the  orchard,  as  well  as  the  worst  branches  on  trees  which  are 
not  seriously  attacked.  Then,  to  prevent  further  injury  from 
the  fungus,  spray  both  large  and  small  trees  with  some  good 
fungicide,  as  the  Bordeaux  mixture.  The  applications  should 
be  made  as  soon  as  the  first  leaves  appear.  Two  applications 
should  be  sufficient,  the  second  one  being  made  eight  or  ten  days 
after  the  first.  During  rainy  seasons  it  may  be  well  to  repeat 
the  operation  a  third  time.  "The  planting  of  resistant  varieties 
is  one  of  the  best  methods  of  escaping  the  disease.  See  QUINCE. 

Scab  (Fusicladium  dendritic um,  Fckl.).  —  Description.  This 
fungus  attacks  the  fruit  and  the  leaves  of  both  apple  and  pear 
trees.  Upon  the  fruit  it  forms  dark,  circular  spots,  the  largest 
being  about  half  an  inch  in  diameter  (Fig.  38).  These  spots 
are  often  close  together  or  unite  to  form  surfaces  which  may 
extend  over  a  considerable  area.  The  centers  of  the  spots  are 
dark  brown  or  black  in  color,  but  at  the  edges  there  is  a  light 
gray  or  white  circle.  This  appearance  is  due  to  the  separation 
of  the  outer  skin,  or  cuticle,  from  the  tissue  beneath.  When 
the  diseased  area  is  large,  it  generally  cracks,  and  then  the 
hard,  brown  tissue  within  the  apple  may  be  seen  (Fig.  39). 
Growth  is  checked  in  the  diseased  portions  and  the  fruit  is 

i  Orchard  and  Garden,  1S90,  Vol.  xii.  July,  184. 


244  The  Spraying  of  Plants. 

usually  one-sided,  sometimes  to  such  an  extent  that  the  blossom 
end  and  the  stem  are  close  together.  Isolated  spots  do  not 
seriously  injure  the  apple,  but  frequently  its  market  value  is 
thereby  considerably  reduced. 

The  appearance  of  the  disease  upon  the  leaves  is  similar  to 
that  upon  the  fruit,  but  the  light-colored  edge  is  wanting.  The 
parts  attacked  are  circular  or  oval,  and  where  several  spots  have 
run  together  the  outline  is  irregular.  The  first  indication  of 
the  presence  of  the  fungus  on  the  foliage  is  the  appearance  of 


FIG.  38.  —  Fall  Pippin  apple  disfigured  by  scab. 

small,  light  green  areas  which  are  easily  distinguished  when  the 
leaf  is  held  up  to  the  light.  In  a  few  days  the  central  portions 
of  these  areas  become  raised,  causing  the  leaf  to  become  more 
or  less  distorted.  The  color  at  the  same  time  changes  to  a  dull 
brownish-black,  which  is  plainly  visible  upon  the  upper  side  of 
the  leaf.  This  causes  the  leaf  to  curl,  the  concave  or  hollow 
side  being  underneath  ;  the  edges  of  the  leaf  often  become 
brown  and  torn.  (For  colored  plate  of  scab,  see  Cornell  Bull.  84.) 
The  scab  is  undoubtedly  the  most  serious  fungous  disease 
with  which  the  apple  grower  has  to  contend.  No  other  disease 
annually  ruins  such  a  large  percentage  of  the  crop.  From  the 


Apple. 


245 


fact  that  the  fungus  also  grows  upon  the  leaves,  it  frequently 
occurs  that  entire  orchards  are  defoliated.  The  result  is  that 
the  tree  receives  so  little  nourishment  that  it  may  not  bear  a 
profitable  crop  for  several  years,  even  though  during  this  time 
it  is  kept  free  from  the  disease.  Wherever  apples  are  grown, 
they  suffer  more  or  less  from  the  parasite.  Some  years  the 


FIG.  39.  —  Severe  attack  of  apple  scab  upon  fruit  and  foliage. 


injury  may  be  so  slight  that  it  is  scarcely  noticed,  and  during 
others  it  may  attack  a  tree  with  such  intensity  that  there  is 
scarcely  enough  fruit  or  foliage  left  to  tell  the  tale  of  the  cause 
of  the  destruction.  Apple  growers  in  western  Xew  York  and 
in  southern  Michigan  will  bear  evidence  of  the  condition  of 
orchards  in  the  summer  and  fall  of  1892  and  1893.  The  trees, 
especially  iu  Michigan,  appeared  as  if  burned  by  fire,  and  it  was 


246  The  Spraying  of  Plants. 

said  that  in  some  counties  there  was  not  produced  one  car-load 
of  first-class  fruit.  It  is  no  wonder  that  apple-growing  does  not 
always  pay.  The  wonder  is  that  it  ever  does  pay,  when  the 
care  given  the  orchard  is  considered.  The  causes  of  the  many 
failures  are  principally  two:  first,  the  neglect  of  the  top,  as 
regards  pruning,  spraying,  and  similar  operations ;  second,  the 
neglect  of  the  roots,  as  regards  feeding  and  the  condition  of 
the  soil.  It  rests  entirely  with  the  grower  if  his  trees  shall 
produce  scabby  fruit  or  perfect  fruit.  He  can  make  his  choice, 
and  the  outcome  will  be  as  he  chooses.  In  this  statement,  no 
variety,  however  susceptible  it  may  be  to  the  attacks  of  the  scab, 
is  excepted.  Some  varieties,  as  the  Spitzenberg,  Fameuse,  Fall 
Pippin,  Early  Harvest,  and  in  many  localities  the  Baldwin, 
seldom  produce  uniformly  good  fruit,  and  with  few  exceptions, 
the  last  has  been  far  from  perfect  during  the  past  few  years. 
Ben  Davis,  King,  Fallawater,  and  many  other  varieties  are  not 
nearly  so  much  affected  by  the  scab.1  These  varieties  need  less 
care  and  often  produce  very  fair  crops  without  any  special 
attention,  but  in  such  cases  they  generally  bear  in  years  of 
plenty,  when  prices  run  low  except  for  extra  fine  fruit. 

Treatment.  Treatment  of  the  apple  scab  should  begin  early  in 
the  season.  This  was  forcibly  shown  in  the  spring  of  1892.2 
The  first  application,  using  Bordeaux  mixture,  was  made  June 
13,  about  one  week  after  the  blossoms  had  fallen  from  the  trees. 
At  the  time  of  the  second  application,  June  22,  small  portions 
affected  with  the  scab  fungus  could  occasionally  be  found  upon 
the  apples  in  places  thickly  covered  by  the  Bordeaux  mixture 
previously  applied.  These  portions  were  undoubtedly  attacked 
before  the  first  application  was  made.  As  this  occurred  soon 
after  the  blossoms  fell,  it  is  clear  that  the  trees  were  sprayed  too 
late.  They  should  receive  at  least  one  application  before  the 
blossoms  open.  The  value  of  this  has  been  demonstrated  in 
another  way.  D.  G.  Fairchild  observed  the  growing  mycelium 
upon  apple  twigs  even  before  the  buds  broke,  and  this  would 
indicate  that  for  very  susceptible  varieties  it  may  be  well  to 
spray  with  a  solution  of  the  sulphate  of  copper  when  the  buds 
are  swelling. 

1  Cornell  Agric.  Exp-  Sta.  Bull.  48,  288-290. 

2  For  detailed  account  of  experiments  in  the  treatment  of  apple  scab,  see  Cornell 
Agric.  Exp.  Sta.  Bull.  48,  265-274 ;  also  Bulletins  60  and  86. 


Apple.  247 

A  second  application  should  be  made  just  before  the  blossoms 
open,  and  a  third  as  soon  as  the  blossoms  have  fallen  from  the 
trees ;  but  for  these,  as  well  as  for  all  later  ones,  it  is  advisable 
to  use  the  Bordeaux  mixture  or  some  similar  preparation.  Such 
applications  may  be  made  at  intervals  of  ten  or  fifteen  days, 
depending  upon  the  weather,  until  from  two  to  six  have  been 
made.  The  number  necessary  will  depend  largely  upon  the 
variety  treated.  In  comparatively  dry  seasons,  two  applications 
will  afford  almost  complete  protection  to  resistant  varieties, 
while  those  subject  to  the  disease  would  repay  as  many  as  four 
or  five.  When  so  treated,  the  fruit  and  the  foliage  will  be 
practically  perfect  as  regards  injury  from  scab. 

The  amounts  of  liquid  necessary  to  protect  an  apple  tree  from 
the  scab  will  vary  with  the  size  of  the  tree  and  with  the  season. 
A  well-grown  apple  tree,  twenty-five  years  old,  will  require  from 
two  to  three  gallons  of  liquid  when  sprayed  before  the  blossoms 
open.  Later  in  the  season,  when  the  tree  is  in  full  leaf,  it  will 
be  necessary  to  use  four  or  perhaps  five  or  even  six  gallons  to 
cover  the  leaves  and  the  fruit  thoroughly. 

INSECT  ENEMIES. 

Aphis  (Aphis  Mali,  Fabr.). — Description.  These  small  insects, 
commonly  called  lice,  are  often  very  numerous  upon  the  young 
shoots  and  leaves  of  apple  trees.  They  are  generally  most 
abundant  in  spring  and  early  summer,  and  in  the  fall.  They 
are  supposed  to  cause  considerable  damage  by  sucking  the  juices 
from  the  blossoms  and  young  leaves,  but  the  injury  done  by 
them  has  probably  been  overestimated.  During  the  latter  part 
of  June  and  July  the  insects  disappear.  While  they  are  pres- 
ent, immense  numbers  may  be  found  upon  the  stems  and  under 
side  of  the  leaves,  the  latter  being  curled  so  that  the  pest  is 
very  well  protected  from  any  application  which  may  be  made. 

Treatment.  Unless  the  lice  are  very  abundant  it  is  not  neces- 
sary to  try  to  destroy  them,  for  they  do  not  cause  any  serious 
damage,  and  in  a  short  time  they  naturally  disappear.  It  is  not 
advisable  to  spray  entire  orchards,  although  they  may  be  badly 
infested.  But  if  it  is  desired  to  destroy  the  lice  upon  certain 
trees,  a  cheap  and  efficient  remedy  will  be  found  in  tobacco 
water,  or  in  the  decoction.  This  should  be  sprayed  upon  the 
trees  as  soon  after  the  lice  have  appeared  as  possible,  and  the 


248  The  Spraying  of  Plants. 

applications  should  be  repeated  at  intervals  of  two  to  four  days 
if  the  insects  persist.  Kerosene  emulsion  is  also  an  excellent 
remedy,  but  it  is  more  expensive.  The  lice  are  veiy  easily 
killed,  and  any  of  the  insecticides  which  kill  by  contact  will 
destroy  them. 

Borers  (a)  Flat-headed  borer  (Chrysobothrisfemorata,  Fabr.) ; 
(&)  Round-headed  borers  (Saperda  Candida,  and  S.  cretata,  Fabr.). 
—  These  insects  cannot  be  controlled  by  spraying.  Various 
washes  containing  carbolic  acid,  clay,  and  many  other  ingre- 
dients have  been  recommended  to  drive  or  keep  the  insects 
from  the  trees,  but  none  have  proved  to  be  of  much  value. 
The  best  and  safest  line  of  treatment  is  to  dig  out  the  larvae, 
or  to  run  a  wire  into  the  burrow  until  the  insects  are  reached. 

Bud-Moth  (Tmetocera  ocellana,  Fabr.).  —  Description.  The 
adult,  also  known  as  the  eye-spotted  bud-moth,  measures  about 
three-fourths  of  an  inch  across  the  fore  wings.  "  The  head, 
thorax,  and  basal  third  of  the  fore  wings,  and  also  the  outer 
edge  and  fringe  are  dark  ashen  gray,  the  middle  of  the  fore 
wings  is  cream  white,  marked  more  or  less  with  costal  streaks 
of  gray,  and,  in  some  specimens,  this  part  is  ashy  gray,  but 
little  lighter  than  the  base.  .  .  .  The  hind  wings  above  and 
below  and  the  abdomen  are  ashy  gray.  The  under  side  of  the 
fore  wings  is  darker,  and  has  a  series  of  light,  costal  streaks  on 
the  outer  part."  1  The  insect  appears  to  have  but  a  single  brood 
in  the  North.  The  eggs  are  laid  during  June  and  July.  Accord- 
ing to  Slingerland,2  these  hatch  in  from  seven  to  ten  days ;  the 
larvae  feed  upon  the  foliage  until  about  half  grown,  this  requir- 
ing a  period  of  about  six  weeks.  They  then  form  a  small 
silken  case,  well  concealed  in  the  crevices  of  the  twigs,  and 
there  they  remain  until  the  following  spring.  When  the  buds 
are  swelling,  and  even  after  they  have  burst,  the  larvae  again 
appear.  They  are  then  small  and  dark  brown,  "about  one- 
fourth  of  an  inch  in  length,  with  a  shining  black  head  and 
thoracic  shield."  3  They  injure  large  trees,  and  also  those  in 
the  nursery ;  in  the  latter  case  they  are  particularly  destructive, 
since  the  future  shape  of  the  tree  may  be  seriously  affected  by 
the  loss  of  the  terminal  buds.  The  opening  buds  are  eaten  and 

1  Fernald,  Mass.  Hatch.  Afjrio.  Exp.  Sla.  1891,  April,  Bull.  12,  7. 

2  Cornell  Agrie.  Exp.  Sta.  1893,  March,  Bull.  50,  14. 
8  Ibid.  10. 


Apple. 


249 


also  the  young  foliage,  so  that  even  large  trees  frequently  suffer 

severely  from  the  insect.     The  young  growing  leaves  are  drawn 

together  and  firmly  held  by  means  of  silken  threads,  and  in 

this  retreat  the  larvae  are  well  sheltered  (Fig.  40).     The  insect 

pupates  within  this  mass  of  foliage 

six  or  seven  weeks  after  its  first 

appearance   in   spring,   and   about 

ten   days  later  the  adult  appears. 

Eggs  are  laid  after  three  or  four 

days,  and  thus  the  life  circle  of  the 

insect  is  completed. 

Treatment.  The  insect  may  be 
quite  easily  destroyed  by  thoroughly 
spraying  the  affected  trees  with 
arsenical  poisons  as  soon  as  the 
buds  have  opened,  so  that  the  tips 
of  the  young  leaves  may  be  seen. 
Two  applications,  made  before  the 
blossoms  open,  should  prove  en- 
tirely effective  in  the  destruction 
of  this  insect. 

Canker-worm  (Anisopteryx  pome- 
taria,  Harris).  —  Description.  This 
insect  is  commonly  called  the  fall  canker-worm,  and  another 
species,  Paleacrita  vernata,  Peck,  is  known  as  the  spring  canker- 
worm  ; 1  they  are  frequently  termed  measuring  worms,  from  the 
peculiar  manner  in  which  they  move  about  (Fig.  41). 

The  caterpillars  vary  in  color  from  yellow  to  dark  brown, 
and  are  variously  striped.  When  mature  they  are  about  an 
inch  long.  They  then  leave  the  tree  upon  which  they  have 
been  feeding,  either  by  crawling  down  the  trunk  or  by  lower- 
ing themselves  from  the  branches  by  means  of  a  fine  thread. 
They  enter  the  ground  and  spin  cocoons.  Here  they  remain 
until  fall,  when  the  adult  moths  appear.  The  male  (Fig.  42) 
has  a  wing  expanse  of  about  one  and  one-fourth  inches.  It  is 
of  a  glossy  gray  color,  two  irregular  white  bands  being  gener- 
ally found  upon  each  of  the  fore  wings.  The  female  is  wing- 
less (Fig.  43),  from  one-fourth  to  nearly  half  an  inch  in  length, 
and  is  also  gray  in  color.  She  soon  crawls  up  the  trunk  of  the 

i  Saunders,  "  Insects  Injurious  to  Fruit,"  1889,  46. 


FIG.  40. — Young  apple  foliage  in- 
jured by  larra  of  bud-moth. 


250 


The  Spraying  of  Plants. 


tree  and  deposits  her  eggs  among  the  branches.  The  adult 
forms  of  the  spring  canker-worm  rarely  appear  in  the  fall,  but 
emerge  early  in  the  following  year.  They  closely  resemble 
A .  pometaria. 

Treatment.    Various  measures  have  been  taken  to  keep  these 
insects  in  check,  the  most  common  being  to  wrap  the  trunk  of 


FIG.  41.  — The  canker-worm  at  work  ;  natural  size. 

the  tree  with  some  material  over  which  the  adult  female  can- 
not crawl  to  lay  her  eggs.  For  this  purpose  tar,  or  any  sticky 
substance,  has  be'en  in  common  use.1  -Cotton  has  been  highly 
recommended.  However,  the  cheapest  and  best  method  to  get 

1  Kaupenleim  and  Dendrolene  are  two  substances  recommended  by  Professor 
Smith  in  Bull.  Ill,  N.  J.  Agric.  Exp.  Sta.  1895,  Sept. 


Apple. 


251 


FIG.  42.  —  Canker- 
worm  moth;  male, 
natural  size. 


rid  of  the  pest  is  to  spray  the  foliage  with  Paris  green  or  Lon- 
don purple.1  This  should  be  done  early  in  the  season,  as  soon 
as  the  caterpillars  make  their  appearance.  If  they  are  seen  to 
be  injuring  the  trees  before  the  blossoms  are 
open,  it  may  be  well  to  make  an  application 
at  that  time.  But  generally  it  is  not  neces- 
sary to  spray  the  trees  till  after  the  blossoms 
have  fallen.  .Never  apply  the  arsenites  to 
fruit  trees  while  they  are  in  blossom,  for  the 
bees  which  are  working  among  the  flowers 
and  assisting  in  the  setting  of  the  fruit  may 
be  poisoned,  to  the  loss  of  their  owner  as 
well  as  to  the  owner  of  the  orchard.  Whether 
bees  are  actually  poisoned  by  arsenites  when 
applied  to  trees  while  in  full  bloom  is  still  a 
disputed  point ; 2  they  probably  are,  and  the  grower  will  do  well 
to  apply  sprays  either  before  or  after  the  trees  have  bloomed. 
It  may  also  be  that  the  injury  done  to  the  delicate  parts  of  the 
flower  by  the  materials  used  is  alone  sufficient  cause  for  avoid- 
ing this  time  to  do  the  work..  The  time  of  blossoming  is  short, 
and  trees  should  not  suffer  if  sprays  are  properly  applied  before 
and  after  this  period. 

If  one  application  of  the  arsenite  is  not  effective  in  ridding 
the  trees  of  worms,  others  should  be  made  at  intervals  of  eight 
or  ten  days  until  the  pest  is  overcome.  When  the  worms  are 
young,  they  most  commonly  feed  upon  the 
under  side  of  the  leaves,  and  it  is  a  good  plan 
to  treat  these  parts  thoroughly.  In  making 
the  applications  it  must  be  remembered  that 
the  worms  will  not  be  destroyed  unless  the 
poison  is  placed  upon  the  leaves.  All  parts 
of  the  tree  should  be  drenched,  and  if  many 
worms  remain  a  few  days  after  such  an  appli- 
cation, the  materials  used  are  faulty,  or  they 
have  not  been  mixed  in  the  proper  proportions. 

Cigar-case-bearer;    Case-worm   (Coleophora   Fletcherella,  Fer- 
nald). — Description.     The    appearance   of    this    insect    is    so 

i  See  Bailey,  Cornell  Agric.  Exp.  Sta.  1895,  Bull.  101. 

1  Cook,  Mich.  Agric.  Exp.  Sta.  2d  Rep.  261.    Webster,  Insect  Life,  Vol.  v. 
No.  2,  121.    Lintner,  Ibid.  Vol.  vi.  No.  2,  181. 


FIG.  43.  —  Canker- 
worm  ;  adult  fe- 
male, natural  size. 


252  The  Spraying  of  Plants. 

remarkable  that  when  it  has  once  been  observed  it  is  readily 
distinguished  in  the  future.  The  insect  may  be  found  upon 
pears  and  apples.  "  The  moth  is  a  very  delicate  and  pretty  steel- 
gray  object.  During  the  day  it  rests  on  a  leaf  with  its  heavily 
fringed  wings  folded  closely  over  its  abdomen,  and  its  long, 
slender  antennae  placed  close  together  and  projecting  straight 
forward  from  its  head.  They  may  be  seen  on  the  leaves  from 
about  June  15  to  July  15." l  Eggs  are  soon  laid  upon  the  young 
leaves,  and  in  the  course  of  about  two  weeks  the  young  cater- 
pillars may  be  seen.  During  the  first  two  or  three  weeks  these 
mine  within  the  leaf,  eating  out  the  green  tissue  and  causing 
the  formation  of  hollow  brown  areas.  The  larvae  then  begin 
the  construction  from  bits  of  the  leaf  of  the  peculiar  cases, 
which  are  shaped  like  a  cigar,  but  only  about  three-eighths  of 
an  inch  long;  in  these  they  find  protection.  About  the  middle 
of  September  the  worms  migrate  to  the  branches,  where  they 
remain  throughout  the  winter.  Early  in  spring,  as  soon  as  the 
first  leaves  appear,  the  larvae  return  to  the  foliage  and  attack 
all  green  parts  of  the  host-plant.  As  the  case  becomes  too 
small  for  the  growing  insect,  the  old  one  is  deserted  and  a  new 
one  made.  The  little  worm  continually  carries  the  case  on  end, 
and  it  obtains  its  food  by  eating  through  the  upper  surface  of 
the  leaf  and  eating  out  the  green  portions  which  are  within 
easy  reach,  causing  the  affected  part  to  turn  brown.  During 
June  the  larvae  pupate,  and  soon  the  adult  again  appears. 

Treatment.  The  case-bearer  is  serious  in  only  a  few  locali- 
ties, and  its  life  history  has  but  recently  been  carefully  studied. 
Although  no  definite  experiments  have  been  made  aiming  at 
the  destruction  of  the  insect,  yet  the  general  opinion  of  all  who 
have  closely  observed  it  is  that  the  larvae  may  be  killed  by 
spraying  the  affected  trees  with  the  arsenite  early  in  the  spring, 
making  one  application  before  the  blossoms  open,  and  two 
after  they  fall,  as  is  done  for  the  codlin-moth. 

Codlin-moth  (Carpocapsa  pomonella,  Linn.^. — Description. 
This  moth  is  about  half  an  inch  long,  and  when  at  rest  has 
the  wings  folded  close  to  its  body.  Its  general  color  is  grayish 
brown.  "  The  fore  wings  are  marked  with  alternate,  irregular, 
transverse,  wavy  streaks  of  ash  gray  and  brown,  and  have  on 
the  inner  hind  angle  a  large,  tawny-brown  spot,  with  streaks  of 

i  Slingerland,  Cornell  Agric.  Exp.  Sta.  1895,  May,  Bull.  93,  219. 


Apple. 


253 


light  bronze  or  copper  color,  nearly  in  the  form  of  a  horseshoe ; 
at  a  little  distance  they  resemble  watered  silk."1  The  hind 
wings  are  of  a  glossy  light  brown  color  (Fig.  44). 

The  moths  first  appear  in  spring,  having  passed  the  winter 
in  cocoons.  The  first  moths  fly  about  the  time  that  the  blos- 
soms fall  from  the  apple  trees,  and  they  continue  to  appear  for 
two  or  three  weeks,  or  even  longer.  Very  soon  after  leaving 
the  cocoons  the  moths  lay  their  eggs,  generally  at  the  blossom 


FIG.  44.  —  Codlin-moth ;  all  parts  natural  size. 

ends  of  the  little  apples.  The  eggs  soon  hatch  and  the  larvae 
immediately  begin  to  eat  the  fruit.  The  second  generation  of 
moths  appears  in  about  six  weeks.  Two  or  three  broods  are 
produced  in  a  season,  and  this  fact  tends  to  increase  the  diffi- 
culty of  treating  the  insect  successfully. 

Treatment.  Formerly  the  principal  remedy  for  the  codlin- 
moth  was  to  destroy  all  the  windfalls,  either  gathering  by 
hand,  or  having  them  eaten  by  stock  which  was  allowed  to  run 
in  the  orchard.  This  practice  was  fairly  successful.  Since 

i  Saunders,  "  Insects  Injurious  to  Fruit,"  1589, 129. 


254  The  Spraying  of  Plants. 

the  moth  is  a  night-flying  insect,  it  has  been  repeatedly  tried 
to  attract  it  by  means  of  lights.  Rarely  is  one  caught,  and  it 
is  useless  to  attempt  to  trap  the  moth  in  this  manner. 

Spraying  with  arsenites  is  rapidly  taking  the  place  of  the 
many  methods  which  were  formerly  employed  to  destroy  this 
pest.  The  applications  are  safe,  easily  made,  and  are  almost 
invariably  followed  by  excellent  results.  The  first  application 
should  be  made  as  soon  as  the  blossoms  fall  from  the  trees,  earlier 
ones  being  unnecessary.  But  as  soon  as  the  blossoms  have 
fallen,  spray  thoroughly,  using  either  Paris  green  or  London 
purple.  The  operation  must  not  be  delayed  until  the  apples 
are  as  large  as  cherries,  but  should  be  immediately  performed. 
It  is  well  to  spray  a  second  time  about  ten  days  later,  but  if  the 
weather  is  rainy,  applications  are  advisable  after  heavy  showers, 
since  the  poison  is  more  or  less  washed  away  by  a  beating  rain. 
Poison  must  be  at  the  blossom  end  of  the  apple  when  the  larva 
appears,  for  when  the  worm  is  once  inside  the  fruit  it  can  no 
longer  be  reached ;  the  first  thing  that  it  eats  should  be  poison. 

Since  the  second  brood  comes  from  the  first,  if  the  first  is 
killed  there  can  be  no  second,  therefore  the  necessity  of  doing 
the  work  well  from  the  beginning.  The  appearance  of  the  later 
broods  is  probably  too  irregular  to  allow  of  successful  treatment, 
and  it  is  not  always  advisable  to  make  special  applications  for 
their  destruction. 

By  applying  a  combination  of  an  insecticide  and  a  fungicide, 
we  can  treat  both  the  codlin-moth  and  the  apple  scab,  thus 
saving  the  labor  of  one  treatment.  The  most  reliable  combi- 
nation thus  far  made  is  that  of  the  Bordeaux  mixture  and 
Paris  green  or  London  purple.  This  combination  is  as  effective 
as  when  separate  treatments  are  made l  against  the  fungus  and 
the  insect.  The  use  of  the  ammoniacal  carbonate  of  copper 
applied  in  connection  with  the  arsenites  has  also  given  good 
results,  and  as  the  mixture  is  more  easily  applied  than  Bor- 
deaux, it  may  in  some  rare  cases  be  given  the  preference 
(see  page  140). 

In  Paris  green  we  have  a  combined  insecticide  and  fungicide, 
already  prepared,  but  the  fungicidal  value  is  not  so  strong  as 
might  be  wished.  Its  use  during  the  past  two  years  has, 
however,  shown  that  it  affords  apples  considerable  protection 

i  Cornell  Agric.  Exp.  Sta.  Bull.  48,  274 ;  60,  274. 


Apple.  255 

against  fungi.  The  foliage  of  susceptible  varieties  may  be 
rendered  fairly  perfect  by  the  arsenite,  and  in  consequence,  the 
vigor  of  the  tree  itself  will  be  considerably  increased.  Its  addi- 
tional value  as  an  insecticide  makes  it  one  of  the  best  remedies 
for  destroying  orchard  pests. 

Stock  is  frequently  pastured  in  bearing  orchards  which  are  in 
permanent  sod,  and  doubts  are  often  expressed  as  to  the  advisa- 
bility of  removing  the  animals  after  the  trees  have  been  sprayed 
with  arsenical  poisons  or  other  materials.  Cook l  has  conducted 
some  experiments  to  test  this  point,  and  in  no  case  could 
he  find  that  horses  or  sheep  were  in  the  least  injured.  He 
applied  much  larger  amounts  of  the  poisons  than  are  generally 
used ;  and  I  have  still  to  hear  of  the  first  case  in  which  pastur- 
ing stock  under  sprayed  trees,  whatever  the  application  may 
have  been,  has  been  followed  by  bad  results.  When  one  con- 
siders how  small  is  the  amount  of  poison  used  per  tree,  the 
small  percentage  of  it  that  falls  to  the  ground,  and  how  little 
of  this  adheres  to  those  parts  of  the  herbage  that  are  eaten,  it 
will  be  seen  that  there  is  practically  no  danger  to  the  stock. 

Curculio  (Anthonomus  quadrigibbus,  Say).  —  Description.  As 
the  name  of  this  insect  indicates,  it  possesses  four  projections, 
these  being  found  on  the  back  at  the  posterior  end  of  the  body. 
They  are  nearly  conical  in  form  and  of  a  brownish-red  color. 
The  general  appearance  of  the  insect  is  brown,  but  a  shade  of 
red  may  also  be  noticed.  Although  it  is  closely  related  to  the 
plum  curculio,  its  body  is  slightly  smaller  and  the  snout  longer ; 
the  entire  length  is  about  one-quarter  of  an  inch.  Its  habits 
are  also  in  some  respects  different.  In  laying  its  eggs  no 
crescent-shaped  mark  is  made,  but  a  hole,  somewhat  enlarged 
at  the  bottom,  is  bored  into  the  small  apple,  and  the  egg  is 
there  deposited.2  The  apple  grows  more  slowly  in  the 
affected  portions,  which  results  in  its  becoming  misshapen,  and 
if  the  fruit  is  stung  several  times  it  will  be  worthless  on  account 
of  its  small  size  and  irregular  form.  Fig.  45  represents  apples 
which  were  injured  by  this  insect  and  also  by  the  plum  curculio, 
another  serious  enemy  of  the  apple. 

Treatment.  The  apple  curculio  rarely  does  much  damage  in 
the  Xorth,  but  in  some  of  the  middle  states  it  is  occasionally 
very  destructive.  The  most  promising  remedy  is  to  spray  the 

i  See  page  283.  *  Gillette,  Iowa  Ex,p.  Sta.  BuU.  11,  493. 


256 


The  Spraying  of  Plants. 


trees  very  thoroughly  with  the  arsenites  early  in  spring.  It 
may  be  advisable  to  make  the  first  application  before  the 
blossoms  open,  and  another  after  their  fall.  The  value  of  such 
applications  is  still  a  disputed  point,  and  it  is  more  fully  dis- 
cussed under  "  Spraying  for  the  curculio,"  page  68.  My  own 
experience  leads  me  to  believe  that  apples  in  thoroughly 
sprayed  orchards  suffer  comparatively  little  from  this  insect. 
Jarring  the  trees  has  also  been  recommended,  but  this  is  not 
always  practicable.  Sheep  and  hogs  may  be  of  service  in  an 


FIG.  45.  —  Apples  distorted  by  curculio  injuries. 


affected  orchard,  but  unfortunately  apples  which  are  stung  by 
the  curculio  do  not  fall  to  the  ground  to  such  an  extent  as  do 
those  attacked  by  the  codlin-moth,  and  only  a  small  number 
would  be  destroyed  by  this  means. 

Fall  Web-worm  (Hyphantria  cunea,  Harris).  —  Description. 
The  mature  insect  is  a  moth,  pure  white  in  color,  with  an  ex- 
panse of  wings  of  about  one  and  one-fourth  inches.  The  insect 
is  widely  distributed  throughout  the  country,  and  when  undis- 
turbed, the  larvse  may  do  considerable  injury,  not  only  to  fruit 
trees,  but  to  many  other  plants,  since  they  are  not  very  par- 


Apple.  257 

ticular  as  to  diet.  The  eggs  are  laid  upon  the  foliage  during 
early  summer,  and  soon  hatch.  The  full-grown  larvae  are  about 
an  inch  long,  with  varied  markings.  They  are  thickly  covered 
with  yellowish  hair,  of  varying  shades,  it  being  longer  at  the 
extremities  of  the  body.  The  head  is  black,  and  a  dark  stripe 
extends  along  the  back.  These  caterpillars  are  most  con- 
spicuous in  the  fall  after  they  have  woven  a  web,  inside  which 
they  work.  The  foliage  to  be  eaten  is  first  enclosed  in  this 
manner,  and  afterwards  devoured.  When  full  grown  the 
caterpillars  descend  to  the  ground,  and  there  spin  cocoons  in 
which  they  remain  until  the  following  year.  There  is  but  one 
brood  of  the  insect  in  the  Xorth. 

Treatment.  Spray  with  the  arsenites  during  summer,  as  soon 
as  the  presence  of  the  insect  is  noticed.  The  foliage  should  be 
covered  with  the  poison  before  it  is  surrounded  by  the  web, 
and  this  can  be  done  most  effectively  while  the  larvae  are 
small.  If  spraying  is  neglected,  cut  out  the  limb  and  burn 
it,  or  hold  a  burning  torch  to  the  nest  until  the  caterpillars  are 
destroyed. 

Leaf-Skeletonizer  (Pempelia  Hammondi,  Riley). —  Description. 
The  larva  of  this  moth  causes  the  curled  and  scorched  appear- 
ance which  is  sometimes  exhibited  by  apple  leaves,  especially 
when  young.  The  worm,  which  is  greenish-brown,  causes  the 
injury  by  eating  the  green  portions  of  the  leaves.  Its  length  is 
about  half  an  inch.  A  web  is  generally  spun,  and  frequently 
several  leaves  are  drawn  together  by  it,  making  an  unsightly 
object. 

Treatment.  The  web  spun  by  the  larvae  affords  them  some 
protection  against  applications  which  are  made;  but  if  the 
arsenites  are  applied  as  soon  as  the  worms  are  seen,  their  work 
should  soon  receive  a  check,  for  new  material  will  soon  be 
required  for  food,  and  this  should  bear  the  poison.  Hand 
picking  has  also  been  recommended  ;  it  is  a  laborious  but 
certain  method  of  destroying  them. 

Maggot;  Railroad-worm  (Trypeta  pomonella,  Walsh).  —  De- 
scription. The  many  small  burrows  frequently  seen  extending 
in  all  directions  throughout  the  flesh  of  an  apple  are  caused  by 
a  greenish-white  footless  maggot  about  one-fourth  of  an  inch  in 
length.  The  mature  form  of  the  insect  is  a  two-winged  fly.  It 
lays  its  eggs  singly  under  the  skin  of  the  apple,  early  in  sum- 

3 


258  The  Spraying  of  Plants. 

mer ;  these  hatch  in  a  few  days,  and  the  maggot,  after  tunneling 
for  about  six  weeks,  leaves  the  fruit,  and  enters  the  ground, 
where  it  pupates.  The  mature  flies  appear  the  following 
summer. 

Treatment.  No  effectual  remedies  are  yet  known.  It  is 
scarcely  possible  that  arsenical  sprays  will  lessen  the  trouble ; 
but  the  destruction  of  the  young  affected  fruit,  if  well  done, 
would  materially  reduce  the  danger  of  injury. 

Oyster-shell  Bark-louse  (Mytilaspis  pomorum,  Bouche). — De- 
scription. The  small  brownish  scales  which  are  commonly  seen 
upon  apple  trees  have  been  secreted  by  a  little  insect  which  may 
be  found  underneath  them  during  the  summer.  The  scale,  or 
shell,  protects  the  insect,  and  the  latter  can  scarcely  be  reached 
by  any  application  made  at  this  time  of  the  year.  But  in  early 
spring  the  scales  contain  a  number  ot  Jight-colored  eggs. 
These  hatch  in  May,  and  during  warm  weather  the  young 
insects  crawl  about,  and  in  a  few  days  attach  themselves  to  the 
bark.  They  then  begin  to  secrete  a  shell  which  soon  resembles 
that  of  the  parent. 

Treatment.  Since  the  bark-louse  is  a  sucking  insect  it  cannot 
be  destroyed  by  arsenites  or  similar  poisons.  Spray  affected 
plants  with  some  insecticide  which  kills  by  contact,  such  as 
kerosene  emulsion,  or  tobacco  water.  These  applications  should 
be  made  before  the  young  insect  has  attached  itself  to  the  bark. 
Before  the  eggs  hatch  it  is  well  to  scrape  badly  affected  parts, 
and  then  to  wash  them  thoroughly  with  some  good  insecticide, 
those  of  a  soapy  nature  being  preferable. 

Tent  Caterpillar  (Clisiocampa  Americana,  Harris).  —  Descrip- 
tion. The  moths  are  three-fourths  of  an  inch  long,  the  spread  of 
the  wings  being  about  one  and  three-fourths  inches.  The  general 
color  is  brown,  but  there  is  a  darker  band  near  the  outer  mar- 
gin of  the  fore  wings.  In  July  the  moths  lay  their  eggs  closely 
in  rows  around  the  smaller  twigs  of  trees,  sometimes  as  many 
as  three  hundred  being  deposited.  These  eggs  do  not  hatch 
until  the  following  spring;  then  the  caterpillars  appear,  and 
begin  to  feed  upon  the  young  leaves.  After  a  few  days  they 
commence  to  spin  their  web,  which  soon  grows  to  be  large  and  un- 
sightly. When  full  grown  the  caterpillars  are  about  two  inches 
long ;  they  are  somewhat  hairy,  and  have  a  white  streak  run- 
ning along  the  center  of  the  back.  The  sides  of  the  body  are 


Apple.  259 

ornamented  with  yellowish  markings,  while  underneath  it  is 
quite  black.  The  worms  mature  in  about  six  weeks  from  the 
time  they  are  hatched.  At  this  time  they  generally  leave  the 
tree  and  seek  some  sheltered  corner  in  which  they  spin  their 
cocoons.  In  three  weeks  moths  issue,  and  eggs  are  again  laid. 

Treatment.  This  insect  does  considerable  damage  if  it  is  left 
unchecked,  but  it  is  so  easily  destroyed  that  there  is  no  need 
of  having  any  trouble  with  it  in  an  orchard.  As  soon  as  a 
nest  is  seen,  the  branch  may  be  cut  off  and  burned,  or  the 
insects  crushed  without  the  removal  of  the  nest.  But  a  much 
better  remedy  is  to  spray  the  foliage  near  the  web  with  arsen- 
ites.  The  caterpillars  always  return  to  the  web  at  night,  and 
they  may  also  be  found  there  in  bad  weather ;  and  if  the  tree 
has  been  sprayed  they  generally  return  there  to  die.  In  spray- 
ing for  the  codlin-moth  sufficient  poison  is  applied  to  rid  the 
orchard  of  this  enemy  also. 

Woolly  Aphis  (Schizoneura  lanigera,  Hausm.).  —  Description. 
This  insect  is  a  small  yellow  plant  louse.  It  is  found  upon  many 
kinds  of  trees,  both  on  the  branches  and  among  the  roots,  and 
causes  injury  by  sucking  the  juices.  The  insect  is  protected  by 
a  woolly  or  mealy  covering,  and  from  this  it  has  received  its 
common  name.  When  the  roots  of  nursery  trees  are  attacked 
the  stock  is  almost  worthless,  for  the  labor  and  expense  of  de- 
stroying the  insects  is  generally  greater  than  the  value  of  the 
stock. 

Treatment.  Affected  branches  may  be  cleaned  by  throwing 
a  strong  stream  of  water  upon  them,  thus  dislodging  the 
insects.  Kerosene  emulsion  and  tobacco  w^ater  will  also  kill 
them,  if  the  applications  are  made  so  thoroughly  that  the 
insecticide  will  penetrate  the  covering.  It  will  probably  be 
found  necessary  to  repeat  them.  Roots  of  trees  standing  in 
the  ground  may  be  treated  with  scalding  water.  If  the  roots 
are  to  be  dipped  into  the  water,  a  temperature  higher  than 
150  degrees  F.  should  not  be  allowed,  and  130-135°  F.  should 
kill  the  insects  after  a  moment's  immersion.  Kerosene  emulsion 
and  tobacco  water  give  good  results.  They  may  either  be 
sprayed  upon  the  roots,  or  these  may  be  dipped  into  the  liquid. 
In  either  case  the  roots  must  be  well  cleaned  before  the  appli- 
cation is  made,  so  that  the  insecticide  will  reach  the  insect.  It 
is  possible  that  the  hydrocyanic  gas  treatment  would  be  of 


260  The  Spraying  of  Plants. 

value  in  treating  young,  dormant  trees  before  setting.  During 
summer  these  insects  multiply  very  rapidly,  and  all  treatments 
should  be  made  early  in  the  season,  and  very  thoroughly.  If 
this  is  not  done,  bisulphide  of  carbon  may  prove  effective, 
although  the  remedy  does  not  yet  appear  to  have  been  used  for 
this  purpose. 

APRICOT. 
FUNGOUS  DISEASES. 

Leaf  Rust.     See  under  PLUM. 

INSECT  ENEMIES. 
Curculio.     See  under  PLUM. 


ASPARAGUS. 

Asparagus  Beetle  (Crioceris  Asparagi,  Linn.). — Description. 
In  many  localities  asparagus  is  seriously  injured  by  a  small, 
dark,  metallic-blue  beetle,  which  is  also  marked  with  yellow 
and  red.  It  passes  the  winter  as  a  beetle,  and  lays  its  eggs  on 
the  young  asparagus  shoots  in  spring.  There  are  two  or  three 
broods. 

Treatment.  The  removal  of  affected  parts  and  the  destruc- 
tion of  the  eggs  will  assist  in  suppressing  the  pest.  Hellebore, 
mixed  with  flour,  1  part  to  10,  has  been  recommended  as  being 
effective  against  the  first  brood  of  larvae,  and  it  is  probable 
that  the  arsenite  would  prove  valuable  if  applied  after  market- 
ing has  ceased. 

ASTER. 
FUNGOUS  DISEASES. 

Leaf  Rust  (Coleosporium  Soncfii-arvensis,  Lev.).  —  Description. 
The  fungus  appears  to  attack  the  leaves  mostly  from  the  under 
side;  here  it  produces  orange-colored  pustules  and  eventually 
causes  the  death  of  the  diseased  leaves. 

Treatment.  Spray  the  plants  early  in  the  season  with  a  clear 
fungicide,  repeating  the  applications  at  intervals  of  two  to  four 
weeks.  Care  should  be  exercised  to  reach  the  under  surface  of 
the  leaves. 


Balm  of  G-ilead,  Bean.  261 


BALM  OF   GILEAD. 
FUNGOUS  DISEASES. 
Leaf  Rust.     See  under  COTTONWOOD. 


BARLEY. 
FUNGOUS  DISEASES. 

"  Barley  is  subject  to  two  loose  smuts,  both  somewhat  like  oat 
smut.  They  may  be  prevented  by  soaking  the  seed  four  hours 
in  cold  water,  letting  it  stand  four  hours  in  a  moist  state  in  sacks, 
and  finally  treating  in  hot  water  as  directed  for  oats  and  wheat 
(which  see),  but  only  for  five  minutes,  and  at  a  temperature  of 
126°  to  128°  F."  i 

BEAN". 

FUNGOUS  DISEASES. 

Anthracnose;  Pod  Rust  (Colletotrichum  Lindemuthianum,  Briosi 
and  Cavara).  —  Description.  This  fungus  attacks  the  stems, 
foliage,  and  fruit  of  bean  plants,  and  is,  perhaps,  the  most 
serious  trouble  against  which  bean  growers  have  to  contend. 
The  seed  may  be  affected  even  before  it  is  sown;  it  is  then 
wrinkled  and  pitted  to  a  greater  or  less  extent,  the  affected 
parts  being  sometimes  only  very  slightly  discolored,  again,  very 
markedly  yellow  or  brown.  The  disease  can  be  carried  from 
season  to  season  by  affected  seed,  and  in  severe  cases  the  young 
plants  are  so  much  injured  by  the  fungus  that  they  are  not  able 
to  appear  above  ground.  Young  seedlings  are  also  destroyed, 
as  the  stem  is  frequently  cut  off  by  the  parasite,  causing  deep 
and  blackened  indentations.  The  large  and  the  small  veins  are 
similarly  attacked,  while  the  green  tissue  of  the  leaf  does  not 
escape.  The  latter  shows  the  trouble  by  the  appearance  of 
dark  discolorations  which  conform  in  shape,  to  a  certain  extent, 
to  the  surrounding  veins.  The  part  first  attacked  soon  becomes 
brittle  and  then  breaks,  leaving  an  irregular  opening  through 
the  leaf.  A  black  discoloration  marks  the  progress  of  the  dis- 
ease. Upon  the  stems  and  veins,  affected  parts  are  consider- 
ably sunken  and  blackened,  the  edges  being  tinged  with  red. 

»  U.  S.  Dept.  ofAgric.  Div.  of  Veg.  Path.  Farmers'  Bull.  No.  5. 


262 


The  Spraying  of  Plants. 


This  is  particularly  noticeable  upon  the  sides  of  diseased  pods 
(Fig.  46).     Later,  the  central  portion  of  the  pits  show  minute, 


FIG.  46.  —  Bean  anthracnose. 


light-colored  dots,  which  are  masses  of  spores  or  reproductive 
bodies.  Spore  formation  appears  to  be  particularly  energetic 
upon  the  pods. 


Bean.  263 

Treatment.  The  use  of  healthy  seed  is  of  the  greatest  impor- 
tance. Diseased  seed  may  be  soaked  in  some  good  fungicide,  but 
the  value  of  the  operation  is  open  to  doubt.  Professor  Beach 
has  made  a  careful  study  of  this  disease,  and  his  conclusion  is 
as  follows  : 1  "  Even  when  the  treatment  of  the  seed  by  the  best 
fungicides  is  so  severe  that  the  stand  is  seriously  injured,  there 
remains  enough  of  the  disease  to  injure  the  crop  under  field 
conditions.  At  the  time  of  harvesting  the  crop  in  the  above 
noted  experiments,  not  a  sound  plant  or  even  a  sound  pod  was 
found  in  the  whole  lot.  These  results  certainly  give  little  en- 
couragement for  hope  that  treatment  of  seed  writh  fungicides 
will  yield  sufficiently  good  results  to  justify  recommending  its 
adoption." 

The  recommendations  made  by  Professor  Beach  in  regard  to 
treating  the  disease  are  :  "  (1)  Selection  of  sound  seed;  (2)  im- 
mediate removal  of  infected  seedlings  from  the  field ;  (3)  keep- 
ing the  foliage  covered  with  Bordeaux  mixture."  A  weaker 
mixture,  one  containing  about  1.5  per  cent  of  copper  sulphate, 
has  given  excellent  results,  and  it  is  harmless  to  foliage.  The 
disease  is  more  severe  in  low,  damp  places,  so  these  should  be 
avoided  as  much  as  possible. 

Rust  (Uromyces  Phaseoli,  Winter).  —  Description.  Diseased 
leaves  first  show  small,  brown  dots  which  are  nearly  circular, 
and  slightly  elevated.  They  soon  discharge  a  brown  powder, 
this  being  the  first  crop  of  spores.  Later,  a  second  crop  of 
spores  is  produced;  these  are  black  in  color,  and  somewhat 
larger  than  the  earlier  form.  The  buds  are  similarly  affected. 

Treatment.  The  free  use  of  Bordeaux  mixture  may  afford 
full  protection  to  exposed  plants,  but  as  yet  no  general  use  of 
the  remedy  has  been  made. 


INSECT  ENEMIES. 

Bean  Weevil  (Bruchus  obtectus,  Say).  —  This  insect  closely 
resembles  the  pea  weevil  in  appearance,  and  their  life  histories 
are  practically  identical.  See  under  PEA. 

1  Some  Sean  Diseases.  A  thesis  in  the  Bot.  Dept.  of  the  Agric.  Coll.  Ames, 
Iowa,  1892,  323. 


264  The  Spraying  of  Plants. 

BEAN,   LIMA. 
FUNGOUS  DISEASES. 

Blight  (Phytophihora  Phaseoli,  Thaxter).  —  Description.  This 
fungus  attacks  the  young  leaves  and  stems,  and  also  the  pods. 
It  generally  appears  during  August  and  September,  and  covers 
the  affected  parts  with  a  dense,  white  covering. 

Treatment.  Spray  the  plants  with  some  clear  copper  com- 
pound before  the  season  when  the  disease  generally  first  appears. 
Two  or  three  applications  should  protect  the  vines. 

BEET. 

Leaf  Spot  (Cercospora  beticola,  Sacc.).  —  Description.  "The 
common  name  well  describes  the  general  appearance  of  the  beet 
leaves  infested  with  this  Cercospora,  for  they  are  at  first  more  or 
less  covered  with  small  light  or  ashy  spots,  which  later  often 
become  holes  by  the  disappearance  of  the  tissue  previously 
killed  by  the  fungus.  .  .  .  Full-sized  leaves  often  become 
mutilated,  and  sometimes  scarcely  more  than  the  framework 
remains."  x  The  spots  are  at  first  surrounded  by  a  band  of  red 
or  purple  (Fig.  47).  The  disease  is  more  or  less  prevalent 
throughout  the  summer  months. 

Treatment.  The  trouble  may  be  controlled  by  the  use  of 
fungicides,  but  as  beet  foliage  is  easily  injured,  the  safest  one 
to  use  is  the  Bordeaux  mixture.  This  may  be  used  of  the 
normal  strength,  or  even  more  dilute.  The  first  applications 
should  be  made  about  the  middle  of  June  or  early  in  July,  de- 
pending upon  the  latitude  and  the  season.  The  foliage  should 
thereafter  be  kept  covered  by  the  material. 

Root  Rot  (Phyllosticta,  sp.).  —  Description.  The  fungus  caus- 
ing root  rot  of  beets  is  particularly  serious  after  the  roots  are 
stored.  The  affected  parts  shrink  slightly,  turn  black,  yet 
remain  quite  firm.  The  leaves  appear  to  be  affected  by  the 
same  fungus,  its  presence  causing  the  formation  of  circular 
spots,  sometimes  half  an  inch  in  diameter.  The  diseased  tissue 
dies  and  soon  cracks. 

Treatment.     The  foliage  should  be  well  protected  by  the  Bor- 

i  Halsted,  &.  J.  Agric.  Exp.  Sta,  1895,  Bull.  107,  8. 


Beet. 


265 


deaux  mixture  during  the  growing  season,  and  when  the  beets 
are  stored  all  the  leaves  should  be  removed. 

Rust  (  Uromyces  Betce,  Pers.).  —  Description.  This  disease  is  at 
present  most  destructive  in  Europe  and  in  California.  It  is 
easily  recognized  by  the  rusty-red  powder  that  is  abundantly 
produced  upon  the  affected  portions  of  the  leaves.  A  similar 
disease  attacks  carnations  and  hollyhocks. 


FIG.  47.  —  Beet  leaf  spot. 

Treatment.  Although  it  appears  that  no  definite  experiments 
have  been  made  in  this  country  for  the  control  of  beet  rust,  it 
is  probable  that  the  fungus  may  be  held  in  check  by  continued 
applications  of  the  Bordeaux  mixture.  The  related  forms  found 
upon  other  plants  yield  to  treatment,  and  applications  made 
at  the  first  appearance  of  the  trouble  should  prevent  it  from 
becoming  serious. 

Scab  (Oospora  scabies,  Thax.).  —  This  disease  also  attacks 
potatoes,  causing  them  to  be  scabby.  The  only  known  remedy 
for  the  trouble  in  beets  is  to  avoid  ground  in  which  the  fungus 
is  known  to  exist. 


266 


The  Spraying  of  Plants. 


BLACKBERRY. 

The  insect  and  fungous  troubles  of  the  blackberry  are  treated 
under  RASPBERRY,  which  see. 


CABBAGE. 


FUNGOUS  DISEASES. 


Club-root ;  Club-foot ;  Finger-and-Toe  (Plasmodiophora  Brassi- 
cce,  Woronin).  —  Description.  As  its  name  indicates,  this  disease 
causes  distinct  and  marked  swellings 
or  "  clubs  "  at  certain  portions  of  the 
root  system  of  the  cabbage  and  re- 
lated plants;  when  the  attack  is 
severe,  the  roots  are  apparently  all 
united  into  one  large  swelling  wholly 
distinct  from  the  normal  growth  of 
the  plant  (Fig.  48).  The  fungus  caus- 
ing the  disease  may  remain  active  in 
the  soil  for  several  years,  and  the 
young  plants  are  frequently  very 
seriously  attacked  even  before  they 
are  set  in  their  permanent  quarters. 
Affected  plants  appear  weak  and 
sickly,  they  grow  slowly  or  not  at  all, 
and  are  disinclined  to  form  heads. 

Treatment.  Although  club-root  is 
one  of  the  most  serious  of  the  dis- 
eases attacking  cabbages,  its  treat- 
ment is  not  well  understood.  The 
successful  use  of  fungicides  appears 
to  be  hopeless,  and  until  some  means 
of  destroying  the  fungus  in  the  soil 
has  been  discovered,  the  best  plan  of  overcoming  the  parasite  is 
to  starve  it  out  by  growing  other  crops  upon  the  land.  It  has 
been  recommended  that  cabbages  and  allied  plants  should  not 
be  grown  upon  infested  land  oftener  than  once  in  three  years. 
All  material  which  is  capable  of  encouraging  the  growth  of  the 
fungus  should  be  destroyed,  and  the  spread  of  the  disease  should 


FIG.  48.  —  Cabbage  club-root. 


Cabbage.  267 

be  checked  whenever  opportunity  offers.  Halsted  has  success- 
fully treated  club-foot  by  applications  of  air-slaked  stone  lime, 
used  at  the  rate  of  75  bushels  per  acre.  This  remedy  should 
be  given  a  thorough  trial.1 

INSECT  ENEMIES. 

Cabbage  Aphis  (Aphis  Brassicce). —  Description.  This  insect 
is  one  of  the  many  forms  of  plant  lice  with  which  gardeners 
have  to  contend.  It  is  a  small,  greenish-blue  insect  which,  if 
unchecked,  increases  at  an  astonishing  rate.  It  is  almost  con- 
tinually protected  by  a  gray  flour-like  covering  which  renders 
treatment  difficult.  As  with  all  other  insects  which  propagate 
rapidly,  it  is  essential  that  those  found  early  in  the  season  be  as 
completely  exterminated  as  possible. 

Treatment.  Poisons  which  penetrate  the  outer  coverings  of 
the  insect  are  to  be  recommended.  It  is  difficult  to  make  mate- 
rials adhere  to  either  the  foliage  or  to  the  insects,  and  for  this 
reason  they  must  be  all  the  more  carefully  applied;  kerosene 
emulsion,  tobacco  water,  hot  water,  pyre  thrum,  etc.,  are  all 
effective  if  properly  used. 

Cabbage  Plusia  (Plusia  Brassicce,  R.).  —  Description.  The 
adult  insect  is  a  dark-gray  moth  about  an  inch  in  length  hav- 
ing a  small  silvery  spot  and  V-shaped  mark  in  the  center  of 
each  fore  wing.  The  moths  appear  in  spring  and  lay  their  eggs 
generally  on  the  upper  side  of  the  cabbage  leaf.  They  hatch 
into  green  larvae  which  feed  upon  the  foliage  of  the  plant,  fre- 
quently burrowing  through  and  through  the  cabbage  head, 
practically  ruining  it  for  market.  The  worms  also  feed  upon 
lettuce,  endive,  celery,  and  other  garden  plants,  their  treatment 
being  the  same  as  here  described.  These  worms  are  span-worms ; 
they  progress  by  looping  the  body  and  then  straightening  it. 
When  full  grown  they  are  about  one  and  one-half  inches  in  length. 
The  larvae  then  spin  cocoons,  pupate,  and  in  a  short  time  the 
adult  moth  appears.  There  is  more  than  one  brood  each  season. 

Treatment.  The  remedies  mentioned  under  CABBAGE-WORM 
may  be  used  successfully  against  this  pest  also.  But  if  pos- 
sible, greater  care  should  be  exercised  in  destroying  the  plusia, 
since  on  account  of  its  tunneling  habits  it  inflicts  more  damage 

i  N.  J.  Agric.  Exp.  Sta.  7th  Ann.  Kept.  1894,  288. 


268  The  Spraying  of  Plants. 

on  the  crop.  The  first  brood  should  be  exterminated  by  repeated 
and  thorough  applications. 

Cabbage  Root-maggot  (Phorbia  Brassicce,  Bouche). —  Descrip- 
tion. The  adult  insect  is  a  two-winged  fly  which  bears  much 
resemblance  to  that  so  commonly  found  in  and  about  dwelling- 
houses.  It  is  considerably  smaller,  however,  and  the  wings 
fold  more  closely  together. 

The  adult  flies  appear  during  April  and  early  May.  Eggs 
are  laid  about  the  base  of  the  newly  set  plants,  in  some  cases 
several  hundred  being  found  about  a  single  plant.  These  ap- 
pear to  hatch  in  about  a  week,  depending  upon  the  condition  of 
the  weather.  The  young  maggots  generally  first  attack  the 
young  roots,  burrowing  along  their  surfaces,  until  finally  the 
root  is  destroyed.  The  main  roots  are  then  attacked,  and  later 
the  stem  of  the  plant  may  be  entered.  In  this  manner  a  crop 
is  soon  rendered  worthless.  There  appear  to  be  two,  and  pos- 
sibly three  broods  each  year. 

Treatment.  The  cabbage  root-maggot  has  for  years  been 
causing  serious  losses  to  cabbage  growers,  and  although  about 
seventy  methods  of  destroying  the  pest  have  been  recommended, 
only  few  have  much  merit,  showing  that  the  enemy  is  a  difficult 
one  to  deal  with.  Pieces  of  tar  paper  fitted  closely  about  the 
young  plants  at  the  time  of  setting,  or  immediately  after,  are 
very  effective  in  preventing  the  flies  from  laying  their  eggs. 
As  the  insect  works  upon  many  weeds,  and  also  upon  other  cul- 
tivated plants,  this  method  does  not  destroy  the  pest,  but  drives 
it  to  other  quarters,  from  which  future  supplies  may  at  all  times 
come.  Another  and  better  plan  is  to  inject  about  a  teaspoon- 
f  ul  of  the  bisulphide  of  carbon  just  underneath  the  plant,  avoid- 
ing contact  with  the  roots  as  much  as  possible.  In  severe  cases 
a  tablespoonf  ul  may  be  used  to  advantage.  One  application,  if 
made  when  the  maggots  are  first  seen  in  May,  should  be  suffi- 
cient. After  applying  the  liquid,  press  the  soil  about  the  plant, 
to  prevent,  as  far  as  possible,  the  escape  of  the  fumes.1 

CABBAGE-WORM. 

Imported  Cabbage-butterfly  (Pieris  Rapce,  Linn.).  —  Description. 
Our  common  cabbage-worm,  although  a  species  introduced  from 

1  For  an  exhaustive  account  of  this  insect,  see  Slingerland,  Cornell  Agric.  Exp. 
Sta.  1894,  Bull.  78. 


Cabbage.  269 

Europe,  has  become  so  widespread  and  serious  that  many  cab- 
bage crops  are  annually  ruined  by  it.  Gardeners  are  only  too 
familiar  with  the  mature  and  the  larval  forms  to  require  com- 
plete descriptions  for  the  identification  of  the  insect.  The 
adult  is  a  white  butterfly  having  the  outer  fore  corner  of  the 
front  wings  marked  with  black.  In  addition  to  this  the  male 
has  one  black  spot  near  the  center  of  the  front  wings,  while  the 
female  has  two.  The  insects  pass  the  winter  in  the  chrysalis 
state,  and  in  spring  the  mature  forms  appear.  The  female  lays 
her  eggs,  which  are  small  and  of  a  yellow  color,  upon  the  leaves 
of  cabbages  and  related  plants ;  in  a  few  days  the  eggs  hatch, 
producing  small  green  worms  that  feed  upon  the  foliage  of 
the  plants  upon  which  they  were  laid.  These  worms  become 
full  grown  in  about  two  weeks,  when  they  seek  some  sheltered 
place  in  which  they  turn  to  pupae.  In  from  one  to  two  weeks 
a  new  crop  of  butterflies  may  be  seen,  and  these  in  turn  con- 
tinue to  propagate  the  species.  Several  broods  appear  each  year. 

Treatment.  This  pest  is  most  easily  destroyed  when  it  is  in 
the  larval  stage.  It  may  then  be  treated  in  two  general  ways. 
As  the  larvae  eat  the  foliage  they  may  be  poisoned  very  easily 
by  applying  hellebore  or  some  form  of  arsenic.  The  latter, 
however,  must  be  used  only  upon  young  plants,  otherwise  there 
is  danger  of  poisoning  the  human  consumer.  Hellebore  may 
be  used  quite  freely  at  i  all  times,  since  it  loses  its  strength  on 
exposure  to  air.  The  other  method  of  destroying  the  insects  is 
to  apply  poisons  which  penetrate  the  soft  covering  of  their 
bodies.  For  this  purpose  kerosene  emulsion  may  by  success- 
fully employed,  but  as  in  the  case  of  the  arsenites,  only  young 
plants  should  be  treated  in  this  manner.  For  heading  cabbages, 
it  is  safer  to  use  some  form  of  pyrethrum.  Some  prefer  the  use 
of  hot  water  to  all  other  remedies ;  it  is  clean,  does  not  injure 
the  plants  if  properly  applied,  and  it  destroys  the  worms.  It 
is  unpleasant  to  handle,  however,  and  its  use  has  not  generally 
been  favored.  Particular  care  should  be  taken  to  kill  the  first 
brood,  whatever  the  remedy  selected,  for  if  this  brood  is  exter- 
minated, later  ones  will  have  small  chances  of  appearing.  All 
applications  should  be  repeated  as  often  as  seems  to  be 
necessary. 

Harlequin  Cabbage-bug  (Murgantia  histrionica,  Hahn).  —  De- 
scription. This  southern  insect  is  gradually  extending  north- 


270  The  Spraying  of  Plants. 

ward  along  the  Atlantic  coast,  and  is  showing  itself  to  be  per- 
haps the  worst  enemy  of  the  cabbage  grower.  The  adult  bug 
is  nearly  half  an  inch  in  length.  It  is  brightly  marked  with 
black  and  orange  colors,  and  for  this  reason  has  received  its 
popular  name.  The  mature  insect  hibernates  during  the 
winter ;  in  early  spring,  as  soon  as  the  cruciferous  plants  upon 
which  it  feeds  make  their  appearance,  the  eggs  are  laid,  com- 
monly on  the  under  side  of  the  leaves,  and  closely  cemented  in 
a  double  row  containing  about  a  dozen  eggs.  These  hatch 
within  a  week,  and  the  young  pests  then  begin  to  suck  the  sap 
from  the  leaves.  So  active  are  their  operations  in  this  direction 
that  it  is  said  a  young  cabbage  plant  will  succumb  in  one  day 
if  attacked  by  half  a  dozen  of  the  insects.  The  bugs  are  very 
shy,  and  if  disturbed  they  try  to  hide.  They  mature  in  about 
twelve  days  from  the  time  the  egg  is  hatched,  and  this  allows 
of  the  appearance  of  several  broods  each  year. 

Treatment.  For  several  reasons  this  insect  is  very  difficult  to 
control.  It  cannot  be  destroyed  by  poisons  which  are  taken  in- 
ternally, and  on  account  of  its  active  habits  it  is  difficult  to 
reach  with  external  applications;  again,  the  rapidity  with  which 
it  can  multiply  renders  very  thorough  work  necessary  from  the 
start,  else  their  number  will  soon  increase  to  an  extent  sufficient 
to  ruin  the  cabbage  plants.  Hand  picking  has  been  recom- 
mended, but  it  is  of  doubtful  value  when  large  areas  are  af- 
fected. One  habit  of  the  pest  may  prove  of  considerable  service 
in  its  destruction.  During  the  nights  of  spring  and  autumn,  the 
adult  insects  collect  under  chips,  boards,  etc.,  and  under  small 
piles  of  leaves  or  some  similar  materials  which  afford  them  good 
hiding-places.  If  these  are  removed  or  burned  in  the  morning 
after  the  insects  have  collected  under  them,  large  numbers  may 
be  disposed  of.  This  practice  is  particularly  valuable  if  the 
brood  which  hibernates  during  the  winter  can  be  so  destroyed, 
since  this  largely  reduces  the  abundance  of  the  future  genera- 
tions. Another  method  of  destroying  this  brood  and  of  saving 
the  cabbage  plants  has  been  suggested  by  Weed.  The  harlequin 
cabbage-bug  is  very  fond  of  mustard,  and  if  the  latter  is  sown 
between  the  rows  of  cabbages  almost  all  the  insects  will  collect 
upon  the  mustard.  This  should  then  be  sprayed  with  pure 
kerosene,  and  thus  the  hibernating  bugs  can  practically  all  be 
destroyed. 


Carnation. 


271 


CARNATION. 


FUNGOUS  DISEASES. * 

Anthracnose  (  Volutella  sp.).  — 
Description.  Although  anthrac- 
nose  is  apparently  an  introduced 
disease,  it  has  become  so  wide- 
spread that  it  is  now  one  of 
the  most  serious  of  the  many 
fungi  attacking  carnations.  The 
fungus  causes  grayish -brown, 
sunken  areas  to  appear  at  the 
bases  of  the  leaves,  these  being 
marked  with  small  black  eleva- 
tions covered  with  bristly  points. 
The  parasite  also  grows  in  the 
stems  of  flowering  plants,  caus- 
ing the  parts  beyond  the  affected 
portion  to  suffer  from  want  of 
nourishment,  a  symptom  read- 
ily distinguished  by  an  expe- 
rienced florist.  Cuttings  very 
frequently  contain  the  disease, 
and  for  this  reason  they  cannot 
do  well. 

Treatment.  Avoid  spreading 
the  disease  wrhen  propagating 
the  carnations;  only  healthy 
stock  should  be  used.  If  there 
is  danger  from  infection,  the 
most  promising  method  of  pre- 
venting the  spread  of  the  disease 
is  to  keep  the  plants  growing 
well,  and  to  spray  them  with 
some  good  fungicide,  as  the  Bor- 
deaux mixture.  To  avoid  stain- 
ing the  plants,  the  ammoniacal 

1  See,  also,  Atkinson,  Carnation  Dis- 
eases. A  paper  read  before  the  American 
Carnation  Society,  1893,  Am.  Fl.  viii.  720. 


FIG.  49.  —  Carnation  rust. 


272 


The  Spraying  of  Plants. 


solution  of  copper  carbonate  may  be  substituted,  although  it  is 
perhaps  not  so  efficient.  The  plants  should  at  all  times  be  pro- 
tected in  this  manner. 

Rust  (Uromyces  caryopliyllinus,  Schr.).  —  Description.  This 
European  disease  was  first  noted  in  this  country  about  the  year 
l.sui.  It  has  IXMMI  rapidly  dissemina- 
~^j  ted  here  by  means  of  the  stock  sent 
out  by  propagators,  and  now  it  can 
be  found  in  the  house  of  nearly  every 
extensive  carnation  grower.  The 
first  external  appearance  of  the  dis- 
ease (Fig.  49)  is  the  formation  of 
gray,  blister-like  elevations  on  the 
leaves  and  stems,  these  being  of 
various  sizes  and  shapes.  As  the 
fungus  develops,  these  parts  rupture 
and  a  large  amount  of  a  reddish- 
brown  powder  is  forced  through  the 
broken  epidermis.  This  powder  con- 
sists of  spores  which  are  capable  of 
reproducing  the  parasite  in  other 
localities.  Later  another  kind  of 
spore  is  matured  from  the  affected 
part,  this  being  of  service  to  carry 
the  fungus  through  conditions  which 
prove  fatal  to  the  body  of  the  para- 
site and  also  to  the  spores  first  pro- 
duced. 

Treatment.  A  plant  that  has  be- 
come infested  with  the  rust  fungus 
cannot  be  cured ;  the  only  remedy  is 
to  cut  out  the  affected  parts  and  de- 
stroy them.  The  spread  of  the  dis- 
ease may,  however,  be  checked  by 
the  proper  use  of  fungicides.  The  disease  appeared  in  the 
Cornell  forcing  houses  during  the  winter  of  1894-95,  and  was 
practically  controlled  by  thorough  applications  of  the  Bordeaux 
mixture.  Copper  chloride  appeared  to  be  equally  effective. 
Soap  was  used  with  the  mixture  in  order  to  make  the  liquid 
adhere  better.  This,  however,  did  not  prove  entirely  satisfac- 


FIG.  50.  —  "  Spot "  of  carnation. 


Carnation,   Cauliflower.  273 

tory,  and  the  greatest  reliance  was  placed  upon  the  production 
of  an  extremely  fine  spray,  the  particles  being  so  small  that 
they  adhered  without  much  difficulty.  If  thorough  applications 
are  made  at  intervals  of  one  to  three  weeks,  little  trouble  should 
be  experienced  from  carnation  rust.  It  is  said  that  the 
disease  may  also  be  controlled  by  the  use  of  the  sulphide  of 
potassium. 

Spot;  Blight  (Septoria  Dianthi,  Desm.). —  Description.  The 
spot  of  carnations  may  be  recognized  by  the  presence  of  grayish- 
brown  spots,  more  or  less  circular  in  outline,  and  surrounded  by 
a  conspicuous  purple  band  which  is  well  defined  on  the  inner 
edge,  but  mingles  with  the  healthy  green  tissue  at  the  outer 
margin  (Fig.  50).  Both  stems  and  leaves  are  attacked,  and 
much  damage  is  inflicted.  The  foliage  cannot  perform  its 
functions  properly,  and  the  stems  may  be  so  severely  attacked 
that  all  portions  beyond  the  diseased  areas  die. 

Treatment.  It  is  probable  that  proper  application  of  fungi- 
cides, as  described  under  RUST,  will  prevent  the  malady  from 
becoming  serious. 

CATALPA. 
FUXGOUS  DISEASES. 

Leaf  Spot  (PJiyllosticta  Ca talpce,  Ell.  &  Martin ).  — Description. 
During  early  summer  the  leaves  of  catalpa  trees  often  become 
disfigured  by  circular  brown  spots  which  under  favorable  cir- 
cumstances increase  to  such  an  extent  that  the  trees  may  almost 
entirely  lose  their  foliage  before  the  middle  of  August.  When 
the  attack  is  less  severe  the  affected  portions  frequently  drop 
from  the  leaves,  causing  the  latter  to  be  more  or  less  perforated. 

Treatment.  Spraying  the  trees  early  in  the  season  with  the 
Bordeaux  mixture  or  some  other  good  fungicide  would  prob- 
ably largely  prevent  the  trouble.  Two  or  three  applications 
made  at  intervals  of  two  or  three  weeks  should  suffice. 


CAULIFLOWER. 

The  enemies  and  diseases  of  cauliflowers  have  been  consid- 
ered under  CABBAGE,  which  see.  Care  should  be  taken  in 
treating  this  crop,  that  the  center  or  "flower"  of  the  plant 
remains  uninjured  by  the  applications. 


274  The  Spraying  of  Plants. 

CELERY. 
FUNGOUS  DISEASES. 

Celery  Blight;  Rust;  Sun-scald  (Cercospora  Apii,  Fries). — 
Description.  The  first  indication  of  celery  blight  is  the  appear- 
ance of  small,  yellowish  spots  upon  the  leaves.  They  rapidly 
enlarge,  run  together,  and  finally  cause  the  destruction  of  the 
leaf,  which  first  turns  yellow  and  then  brown.  The  disease  is 
more  serious  in  dry  locations,  especially  if  the  sun  is  allowed  to 
shine  freely  upon  the  foliage. 

Treatment.  The  crop  should  be  grown  only  in  moist  localities, 
and  there  it  naturally  grows  to  its  greatest  perfection.  If  grown 
on  high  land,  shade  is  desirable;  if  it  can  be  obtained  from  a 
building  so  much  the  better,  as  trees  and  other  growing  plants 
rapidly  dry  out  the  ground  in  their  immediate  vicinity.  In 
case  the  plants  cannot  be  kept  free  from  the  disease  by  these 
means,  the  application  of  any  standard  fungicide  will  almost 
entirely  prevent  its  appearance. 

Leaf  Blight  (Septoria  Petroselini  var.  Apii).  —  Description.  All 
parts  of  the  celery  plant  except  the  roots  suffer  from  this  fungous 
disease.  Watery  areas  appear  on  the  stems  and  leaves,  and 
these  soon  show  many  small  black  dots  which  contain  the 
spores  or  reproductive  bodies  of  the  fungus.  The  disease  is 
very  common  in  seed-beds,  and  may  be  carried  over  on  the  seed. 

Treatment.  The  first  precaution  to  take  is  to  plant  only  clean 
seed.  That  which  is  speckled  or  spotted  with  the  above-men- 
tioned black  dots  should  be  avoided  as  much  as  possible.  If,  in 
addition,  the  young  plants  are  sprayed  with  a  good  fungicide 
the  disease  should  not  become  serious.  Such  applications 
should  be  repeated  whenever  the  condition  of  the  plants  seems 
to  demand  it. 

INSECT  ENEMIES. 

Celery-caterpillar.     See  under  PARSLEY. 

CHERRY. 
FUNGOUS  DISEASES. 

Brown  Rot  (Monilia  fructigena,  Pers.).  —  This  disease  and  its 
treatment  are  fully  discussed  under  PEACH.  The  cherry  does 


Cherry,   Chrysanthemum.  275 

not  require  such  repeated  applications,  since  the  fruit  matures 
earlier  in  the  season.  It  is  also  more  unsafe  to  use  the  Bor- 
deaux mixture,  on  account  of  the  danger  of  staining  the  fruit ; 
the  ammoniacal  solution  of  copper  carbonate  or  some  other 
clear  fungicide  will  be  found  a  better  remedy  after  the  cherries 
are  one-half  grown.  The  Bordeaux  mixture  may  be  safely  ap- 
plied as  soon  as  the  blossoms  have  fallen  and  the  fruit  has  set. 

Leaf  Blight  (Cylindrosporium  Padi.  Karst.).  This  disease  is 
fully  treated  under  PLUM,  which  see. 

Powdery  Mildew  (Podosphcera  Ozycanthce,  DeBary).  See 
under  APPLE. 

Black  Knot  (Plowrightia  [Spkceria]  morbosa,  Sacc.).  See 
under  PLUM. 

INSECT  ENEMIES. 

Canker-worm  (Paleacrita  vernata,  Peck).     See  under  APPLE. 

Plum  Curculio  (Conotrachelus  nenuphar,  Herbst).  See  under 
PLUM. 

Slug  (Selandria  Cerasi,  Peck).  —  Description.  The  mature 
insect  is  a  black  fly  having  four  wings.  The  eggs  are  laid  in 
small  openings  made  in  the  leaf  by  the  insect.  They  hatch  in 
about  two  weeks.  The  larvae  mature  in  about  four  weeks. 
They  bear  a  certain  resemblance  to  a  tadpole,  being  shiny, 
dark-green  worms,  about  half  an  inch  long  (Fig.  75).  They  eat 
the  soft  tissues  of  the  leaves,  only  the  larger  veins  remaining. 
In  severe  cases  the  trees  may  be  entirely  defoliated.  There  are 
two  broods  each  year. 

Treatment.  Fortunately  this  insect  may  be  overcome  very 
easily.  Dry-slaked  lime  dusted  over  the  leaves  destroys  the 
pest,  and  if  air-slaked  lime  be  freely  used  it  will  answer  the 
same  purpose.  Pyrethrum,  hellebore,  or  some  form  of  arsenic, 
applied  dry  or  with  water,  will  also  rid  the  tree  of  the  insect. 
Dry  road-dust  has  been  recommended,  but  is  not  always  satis- 
factory. 

CHRYSANTHEMUM. 
FUNGOUS  DISEASES. 

Leaf  Spot  (Septoria  Chrysanthemi,  E.  &  D.).  —  Description. 
The  fungus  causing  leaf  spot  of  chrysanthemums  first  causes 


276  The  Spraying  of  Plants. 

the  formation  of  small  dark-brown  spots  upon  the  foliage. 
The  affected  areas  increase  in  size  until  the  leaves  are  so  badly 
affected  that  they  fall  to  the  ground.  It  is  only  within  the  last 
few  years  that  the  disease  has  become  serious.  A  leaf  blight, 
caused  by  Cylindrosporium  Chrysanthemi,  E.  &  D.,  closely  resem- 
bles the  leaf  spot  and  is  with  difficulty  distinguished  from  it 
without  the  aid  of  a  microscope. 

New  Leaf  Spot  (Phyllosticta  Chrysanthemi,  E.  &  D.).—  De- 
scription. This  is  another  recent  disease  affecting  chrysanthe- 
mums. It  forms  upon  the  leaves  rather  large  purplish-brown 
areas.  These  appear  soft  and  velvety  upon  the  surface.  When 
a  leaf  is  severely  attacked  the  portions  apparently  unaffected 
turn  yellow,  and  the  value  of  the  leaf  to  the  plant  is  de- 
stroyed. 

Treatment.  Although  these  diseases  have  not  been  exten- 
sively treated,  it  seems  very  probable  that  they  should  be  kept 
in  check  without  much  difficulty.  Bordeaux  mixture  has  in  a 
few  cases  been  used  with  apparent  success ;  and  if  the  applica- 
tions are  thoroughly  made,  and  repeated  at  intervals  of  two  or 
three  weeks,  there  is  every  reason  to  believe  that  the  plants 
may  be  kept  comparatively  free  from  disease.  But  these  fungi 
have  also  proved  to  be  troublesome  in  the  cutting  bench,  and 
here  their  treatment  is  more  difficult.  Only  healthy  stock 
should  be  used  for  propagation,  and  if  the  plants  have  been 
well  grown  this  should  not  be  difficult  to  find.  If  the  diseases 
do  appear  among  the  cuttings,  the  use  of  fungicides  will  un- 
doubtedly be  of  value  in  checking  the  spread  of  the  parasites. 


CORN. 
FUNGOUS  DISEASES. 

Smut  (Ustilago  Maydis,  DC.).  —  Description.  This  fungus 
attacks  all  parts  of  the  corn  plant  above  ground.  It  forms 
large  black  swellings  on  the  stalks,  ears,  and  tassels,  being  espe- 
cially common  in  the  first  two  places  named.  It  is  less  fre- 
quently found  upon  the  leaves.  It  does  the  greatest  damage 
in  the  ear,  for  it  not  only  destroys  much  of  the  grain,  but 
that  which  remains  serves  well  as  a  source  of  infection  to  the 
crop  grown  the  following  year,  provided  any  of  it  is  used  for 
seed. 


Corn,   Cotton.  277 

Treatment.  Effectual  remedies  for  corn  smut  have  not  yet 
been  found.  Some  claim  that  soaking  the  seed  in  a  fungicide 
or  in  hot  water  may  assist  in  preventing  the  trouble,  but  so 
many  cases  are  on  record  in  which  such  treatments  were  of 
practically  no  value  that  they  cannot  be  recommended. 

INSECT  ENEMIES. 

Corn  is  subject  to  the  attacks  of  a  great  many  forms  of 
insects.  As  these  cannot,  however,  be  successfully  treated  by 
means  of  the  remedies  particularly  treated  of  in  this  work,  they 
will  not  be  individually  described.  Those  insects  which  attack 
the  roots  of  corn,  generally  appear  when  the  crop  has  been 
planted  upon  sod  land,  and  as  a  rule  the  older  the  sod  the  more 
numerous  are  the  insects.  Those  which  work  upon  the  parts 
of  the  growing  plants  above  ground  are  perhaps  best  treated  by 
collecting  them  by  hand  and  then  destroying  them.  No  effec- 
tive remedies  are  known  for  several  of  the  pests.  If  the  grain 
is  to  be  stored  it  will  also  be  exposed  to  the  attacks  of  certain 
insects.  These  may  be  destroyed  very  easily  by  the  use  of  the 
bisulphide  of  carbon;  but  the  corn  must  first  be  placed  in  a 
tight  receptacle. 

COTTOK 
FUNGOUS  DISEASES. 

Many  fungous  diseases  of  cotton  have  been  described,1  but 
apparently  no  good  remedies  have  yet  been  discovered. 

INSECT  ENEMIES. 

Leaf-worm;  Cotton-worm;  Cotton-caterpillar  (Aletia  argil- 
lacea,  Iliibn.).  —  Description.  The  adult  insect  is  a  grayish- 
brown  moth  whose  wings  expand  nearly  one  and  one-half 
inches.  The  slender  green  worms  or  caterpillars  begin  to 
appear  in  early  spring,  the  eggs  having  been  laid  upon  the 
under  side  of  the  young  cotton  leaves.  The  number  of  broods 
varies  from  three  to  six,  so  the  transformations  take  place 
rapidly. 

Treatment.  The  arsenites  are  probably  the  best  insecticides 
to  use  in  the  destruction  of  this  insect.  They  may  be  applied 

1  Atkinson,  Ala.  Agric.  Exp.  Sta.  1892,  Dec.  Bulls.  36  and  41. 


278  The  Spraying  of  Plants. 

either  when  mixed  with  water  or  when  dry.  The  latter  method 
is  preferred  by  cotton  planters,  the  undiluted  poison  being  placed 
in  osnaburg  bags  which  are  held  over  the  plants.  Machines 
which  use  the  poisons  diluted  about  ten  times  with  flour  or 
plaster  are  also  made. 


COTTONWOOD. 
FUNGOUS  DISEASES. 

Leaf  Rust  (Melampsora  populina,  Lev.).  —  Description.  Poplar 
and  cotton  wood  trees  are  frequently  attacked  by  a  fungus 
which  produces  an  orange-colored  powder  on  the  under  side 
of  the  leaves.  Such  leaves  may  fall  quite  early  in  the  year,  and 
if  the  attack  is  severe,  the  trees  will  be  partially  or  entirely 
defoliated.  The  winter  stage  of  the  fungus  is  found  upon  the 
under  side  of  the  leaves  also ;  waxy  pustules  of  a  brown  color 
mark  its  presence. 

Treatment.  This  leaf  rust  may  be  checked  by  applications  of 
the  Bordeaux  mixture  made  early  in  the  season  when  the  first 
leaves  have  unfolded ;  the  treatments  should  be  continued  at 
intervals  of  two  or  three  weeks  until  about  the  middle  of 
July. 

INSECT  ENEMIES. 

Leaf-beetle  (Lina  scripta,  Blley).  —  Description.  This  beetle 
is  nearly  three-eighths  of  an  inch  in  length,  of  a  deep,  blue-black 
color,  more  or  less  freely  marked  with  yellow,  or  the  ground 
color  may  be  yellow  and  the  markings  black.  The  adults 
hibernate  during  the  winter,  and  lay  their  eggs  upon  the  young 
foliage.  The  eggs  soon  hatch,  and  the  young  black  grubs 
begin  to  feed  voraciously,  at  the  same  time  growing  rapidly. 
As  the  larvae  grow  older  this  color  becomes  of  a  lighter  shade. 
They  have  the  power  of  emitting  from  the  spines  found  upon 
their  bodies  a  milky  liquid  possessing  a  strong  odor.  There 
are  several  broods  each  year. 

Treatment.  The  arsenites  should  be  freely  used  for  the 
destruction  of  the  first  broods,  and  if  the  insects  appear  again 
during  the  summer,  the  applications  should  be  repeated. 

Willow-worm.      See  under  WILLOW. 


Cranberry. 


279 


CRANBERRY. 
FUNGOUS  DISEASES. 

Gall  Fungus  ;  Red  Rust  (Synchytrium  Vaccinii,  Thomas). — 
Description.  The  presence  of  this  fungus  in  the  cranberry 
plant  irritates  the  latter  to  such  an  extent  that  it  forms  the 
excrescences  or  galls  which  have  given  the  popular  names  to  the 
disease.  These  galls  are  of  a  red  color,  and  in  New  Jersey 
they  generally  appear  upon  the  young  stems,  leaves,  flowers, 
and  fruit,  about  the  first  of  May.  They  are  quite  small,  being 
no  larger  than  one  twenty-fifth  of  an  inch,  both  in  length  and 
in  thickness,  but  they  are  frequently  so  numerous  that  they 
give  to  the  plant  or  even  to  a  bog  a  de- 
cided red  color.  In  such  cases  the 
affected  portions  are  frequently  dwarfed 
and  misshapen.  Some  of  the  spores 
seem  to  ripen  during  the  winter  or  early 
spring,  and  infection  takes  place  during 
the  early  growing  months  of  the  year. 

Treatment.  It  has  been  recommended 
to  burn  affected  parts ;  and  the  sugges- 
tion has  also  been  made  to  keep  the  bog 
dry  during  winter  and  spring.  As  the 
disease  apparently  progresses  by  means 
of  new  infections,  as  do  most  of  the  fungous  diseases  which  are 
under  control,  it  seems  reasonable  to  expect  that  application  of 
such  fungicides  as  the  Bordeaux  mixture  or  the  ammoniacal 
carbonate  of  copper  will  prove  beneficial  if  made  as  soon  as 
growth  begins  in  the  spring.  It  would  probably  be  necessary 
to  make  several  such  treatments,  but  the  flowering  time  of  the 
plants  should  be  avoided  if  possible. 

Scald  ;  Rot.  —  Description.  Scald  of  cranberries  is  produced 
by  a  fungus  which  attacks  the  fruit  during  July  and  August 
(Fig.  51).  The  first  sign  of  the  disease  is  the  formation  of  a 
small,  soft  spot  upon  one  side  of  the  berry ;  or  the  disease  may 
appear  in  different  places  at  the  same  time.  This  affected  part 
soon  extends  throughout  the  entire  berry,  giving  the  latter  the 
appearance  of  having  been  cooked.  It  is  soft  and  of  a  light 
brown  color,  but  the  skin  remains  unbroken.  Later  in  the 
season  the  berry  shrivels  and  may  fall  to  the  ground  or  remain 


FIG.  51.  — Cranberry  scald. 


280  The  Spraying  of  Plants. 

hanging  upon  the  plant.  The  foliage  is  also  affected,  distinct 
brown  areas  appearing  upon  the  leaves.  The  disease  is  most 
troublesome  during  warm,  moist  seasons. 

Treatment.  It  has  been  recommended  to  sand  the  bog  to  the 
depth  of  an  inch  as  a  partial  remedy.  Keeping  the  bog  as  dry 
as  possible  during  the  summer  months  is  supposed  to  be  of  ser- 
vice. The  use  of  properly  applied  fungicides  appears  promis- 
ing, but  the  value  of  these  cannot  yet  be  told. 

INSECT  ENEMIES. 

Fire-worm;  Cranberry-worm;  Vine-worm;  Blackhead  (Rhopo- 
bota  vacciniana,  Packard) .  —  Description.  The  moths  lay  eggs 
on  the  under  side  of  the  leaves  during  the  fall.  These  do  not 
hatch  until  the  following  spring,  the  young  larvae  appearing 
during  the  latter  part  of  April  or  in  early  May.  The  moths 
appear  early  in  June,  laying  their  eggs  about  the  middle  of  the 
mouth.  The  grown  larvae  have  jet-black  heads,  the  body  being 
green  and  having  fine  hairs  scattered  over  the  surface.  They 
feed  upon  the  young  leaves,  and  draw  these  together  by  means 
of  silken  threads.  The  moths  are  grayish-brown,  lighter  col- 
ored bands  extending  across  the  fore  wings;  the  hind  wings  are 
dull  brown.  There  are  two  broods. 

Treatment.  The  bogs  may  be  flooded  after  the  eggs  have 
hatched,  in  this  manner  drowning  the  larvae.  Some  growers 
prefer  to  spray  the  bogs  at  this  time  with  tobacco  water.  Kero- 
sene emulsion  might  answer  the  same  purpose. 

Arsenites,  if  applied  early  and  thoroughly,  have  been  effectual 
in  destroying  these  insects.  Cranberry  foliage  appears  to  be 
susceptible  to  injury  from  these  poisons,  so  that  lime  should  be 
added.  Two  quarts  of  glucose  or  molasses  are  said  to  increase 
their  effectiveness. 

Fruit-worm  (Acrobasis  Vaccinil,  Elley). — Description.  The 
moths  appear  early  in  July  and  lay  their  eggs  upon  the  small 
cranberries,  generally  at  the  blossom  end.  The  eggs  are  small, 
flat,  and  light  yellow  in  color.  They  hatch  in  about  a  week, 
producing  a  little  greenish  worm,  which,  when  mature,  is  about 
half  an  inch  in  length.  These  larvae  first  feed  a  day  or  two  upon 
the  outside  of  the  berry,  after  which  they  enter  the  fruit,  hol- 
lowing it  out,  and  then  another  berry  is  attacked.  The  larvae 
do  not  pupate  till  fall,  passing  the  winter  in  this  condition. 


Cranberry^   Cucumber.  281 

Treatment.  The  habits  of  this  insect  render  it  of  easy  de- 
struction by  the  use  of  the  arseuites.  The  bogs  should  be 
sprayed  as  soon  as  the  fruit  has  set,  and  later  applications  be 
made  at  intervals  of  about  ten  days  as  frequently  as  appears  to 
be  necessary.  Two  treatments  will  probably  prove  to  be  suffi- 
cient in  the  majority  of  cases.  No  danger  of  poisoning  the 
berries  need  be  feared. 

There  are  several  other  insects  which  feed  upon  the  foliage 
and  the  fruit  of  cranberries ;  among  them  may  be  mentioned 
a  weevil,  the  yellow-headed  cranberry-worm,  and  the  tip-worm. 
Proper  applications  of  the  arsenites,  if  made  when  the  insects 
begin  to  cause  trouble,  will  practically  control  the  pests.  Paris 
green  is  on  the  whole  the  safest  insecticide,  but  it  should  be 
used  with  an  equal  volume  of  lime.  Some  farmers  use  tobacco 
water  with  satisfactory  results.  Proper  flooding  will  also  mate- 
rially reduce  the  number  of  insects. 


CUCUMBER. 
FUNGOUS  DISEASES. 

Mildew  (Erysiphe  Cichoracearum,  DC.).  —  Description.  The 
cucumber  mildew  caused  by  this  fungus  is  found  almost  en- 
tirely in  greenhouses.  All  parts  of  the  vines  are  affected, 
although  upon  the  fruit  the  disease  is  not  so  serious.  The 
parasite  grows  merely  upon  the  surface  of  the  plant,  producing 
white,  moldy  areas,  which  appear  as  if  they  consisted  of  a 
white  powder  scattered  thinly  upon  the  affected  part  (Fig.  52). 
These  may  be  so  abundant  that  the  entire  upper  surface  of  a 
leaf  is  covered,  and  the  stems  are  frequently  surrounded  by  the 
fungus  for  a  considerable  distance.  These  spots  may  be  easily 
removed  by  rubbing  the  leaf,  since  the  only  portions  of  the  para- 
site which  enter  the  cucumber  plant  are  small  projecting  threads 
that  enter  the  cells,  and  from  these  the  nourishment  is  drawn. 

Treatment.  Fungi  growing  upon  the  surface  of  the  host- 
plants  may  be  successfully  treated  whenever  they  are  seen,  and 
the  cucumber  mildew  is  no  exception  to  the  rule.  It  mav  be 
controlled  by  spraying  with  a  solution  of  the  liver  of  sulphur, 
the  ammoniacal  carbonate  of  copper,  or  the  Bordeaux  mixture. 
These  should  be  used  at  about  three-fourths  their  normal 
strength,  as  cucumber  foliage  is  tender  and  the  disease  is  not 


282 


The  Spraying  of  Plants. 


FIG.  52.  —  Cucumber  mildew. 


difficult  to  overcome.  The  fumes  of  sulphur  are  also  effective 
in  destroying  the  fungus.  This  mildew  also  attacks  verbenas, 
in  which  case  applications  of  the  sulphide  of  potassium  have 
given  good  results. 


Cucumber.  283 

Powdery  Mildew  (Plasmopara  Cubensis,  B.  &  C. )  See  under 
MUSKMELON. 

INSECT  ENEMIES. 

Melon-louse  (Aphis  Cucumeris,  Forbes).  —  Description.  This 
louse  attacks  cucurbitaceous  plants,  especially  cucumbers  and 
muskmelon  vines,  about  the  middle  of  June.  The  affected 
leaves  curl,  the  edges  turning  downward  and  inward,  and  thus 
affording  protection  to  the  insects,  which  propagate  at  a  very 
rapid  rate.  Large  quantities  of  honey-dew  are  excreted,  and 
in  this  material  a  fungus  grows  which  blackens  the  vines  in  a 
manner  similar  to  that  which  occurs  on  pear  trees  attacked  by 
the  psylla.  Badly  infested  plants  die. 

Treatment.  The  vines  should  be  closely  watched  during  the 
season,  and  the  curling  leaves  should  be  removed  and  destroyed 
with  the  insects  upon  them.  Applications  of  the  Hubbard-Riley 
kerosene  emulsion,  diluted  about  fifteen  times,  made  to  the 
under  side  of  the  leaves  will  be  of  value;  or  whale-oil  soap, 
used  at  the  rate  of  one  pound  to  six  gallons  of  water  and  simi- 
larly applied,  will  also  prove  effective.  The  insect  is  a  difficult 
one  to  keep  under  control. 

Melon-worm  (Eudioptis  hyalinata,  Linn.).  —  Description.  The 
adult  insect  is  a  moth  of  bright,  pearly-white  color.  A  dark 
border  extends  along  the  front  and  outer  edges  of  the  fore 
wings,  and  along  the  lateral  margin  of  the  hind  wings.  The 
larvae  are  a  little  over  an  inch  in  length,  yellowish-green  in 
color,  a  few  hairs  being  scattered  over  the  body.  They  feed 
upon  the  foliage  and  fruit  of  melons,  cucumbers,  squashes,  etc., 
being  particularly  destructive  in  the  southern  states. 

Treatment.  Hellebore  may  be  used  successfully ;  but  the 
arsenites  offer  perhaps  the  best  means  of  destroying  the  insects. 

Spotted  Cucumber-beetle;  Southern  Corn  Root-worm  (Diabro- 
tica,  12-punctata,  Oliv.).  —  Description.  The  adult  insect  is  a 
beetle  about  one-fourth  of  an  inch  in  length.  It  is  yellow  in 
color,  but  has  twelve  black  spots  upon  its  back,  as  its  name 
implies.  The  winter  is  passed  in  the  mature  stage.  The  eggs 
are  laid  in  spring  about  the  roots  of  cucumbers,  squashes,  etc., 
and  in  the  South  corn  is  very  commonly  selected.  The  eggs 
produce  a  slender,  dirty-white  worm,  which  is  about  half  an 
inch  in  length  when  full  grown.  There  are  two  broods  each 


284  The  Spraying  of  Plants. 

year.  The  beetles  feed  upon  the  plants  mentioned  above,  and 
also  upon  other  garden  vegetables. 

Treatment.     See  under  STRIPED  CUCUMBER-BEETLE. 

Striped  Cucumber-beetle  (Diabrotica  vittata,  Fabr.).  —  Descrip- 
tion. The  beetle  appears  early  in  spring  and  attacks  the  leaves 
and  stems  of  the  cucumber  and  related  plants.  Eggs  are  laid, 
these  being  placed  in  the  soil  at  the  base  of  the  plants.  The  eggs 
soon  hatch  and  produce  small  whitish  worms  that  are  about  half 
an  inch  long  when  full  grown.  They  feed  upon  the  roots  of 
the  plants,  causing  the  latter  to  wilt  and  die.  The  larvae  mature 
in  about  two  months,  the  insect  passing  the  winter  in  the  beetle 
form.  It  is  then  very  handsome,  the  back  being  yellow  but 
marked  with  three  black  stripes  running  nearly  the  length  of 
the  wing  covers.  The  length  of  the  insect  is  scarcely  a  quarter 
of  an  inch ;  but  the  pest  is  so  abundant  in  spring  that  serious 
damage  is  inflicted  if  no  steps  are  taken  to  prevent  injury. 

Treatment.  The  more  difficult  it  is  to  destroy  an  insect,  the 
more  remedies  are  recommended,  and  the  very  number  of  these 
is  good  evidence  that  none  are  specifics.  Powders  have  gen- 
erally been  recommended  for  the  destruction  or  disposal  of  the 
two  insects  above  described.  Tobacco  powder,  or  dust,  is  per- 
haps the  best  of  these,  especially  if  a  little  carbolic  acid  be 
added  to  it.  The  powder  may  be  applied  freely  to  the  plants, 
and  applications  should  be  repeated  at  intervals  of  a  few  days, 
selecting  a  time  when  the  plants  are  wet.  In  place  of  the 
above,  it  has  been  recommended  to  use  lime,  plaster,  road-dust, 
etc.,  and  kerosene  may  be  substituted  for  carbolic  acid.  The 
arsenites,  when  used  dry  and  mixed  with  some  of  the  above, 
may  also  possess  considerable  value.  All  application  should  be 
made  early,  and,  if  possible,  to  the  under  side  of  the  leaves. 
Spraying  has  not  yet  proved  satisfactory. 

Plants  are  frequently  protected  by  means  of  a  device  consist- 
ing of  a  light  frame,  as  two  pieces  of  barrel-hoops  crossing  each 
other  at  right  angles,  covered  by  some  fine  mosquito  netting. 
The  frame  is  placed  over  the  young  plants,  and  over  this  is 
spread  the  netting.  The  edges  of  the  latter  must  be  well 
covered  with  earth,  else  the  beetles  will  succeed  in  entering, 
and  when  once  under  the  netting  it  appears  to  be  impossible 
for  them  to  get  out  again.  When  the  plants  have  made  a  good 
growth  the  screens  may  be  removed. 


Currant.  285 

CURRANT. 

FUNGOUS  DISEASES. 

Anthracnose;  Leaf  Blight  (Glceosporium  Ribis,  M.  &  D.). — De- 
scription. During  the  latter  part  of  June  and  early  in  July 
there  occasionally  appears  upon  the  upper  side  of  the  foliage 
of  cultivated  currants  small  brownish-black  spots,  which  are 
as  yet  still  confined  to  the  interior  of  the  leaf  tissue.  As  these 
spots  enlarge,  the  epidermis  on  the  upper  side  of  the  leaf 
becomes  raised  and  loosened,  and  this  gives  a  whitish  appear- 
ance to  the  affected  part,  although  the  general  color  of  the 
diseased  tissue  is  dull  brown.  The  entire  leaf  then  changes  to 
yellow,  and  finally  it  falls  to  the  ground,  this  taking  place  early 
in  August. 

Treatment.  Although  the  disease  has  apparently  remained 
untreated,  it  is  very  probable  that  applications  of  fungicides,  if 
made  thoroughly  and  early  in  the  season,  will  prove  effective 
in  controlling  the  trouble. 

Rust;  Leaf  Spot  (Septoria  Ribis,  Desm. ;  Cercospora  angulata, 
Wiiit.).  —  Description.  This  disease  attacks  all  varieties  of 
currants,  generally  appearing  a  little  before  midsummer.  It 
attacks  the  foliage  of  gooseberries  as  well.  The  first  indica- 
tion of  the  disease  is  the  appearance  of  small  brown  spots  upon 
various  parts  of  the  foliage  (Fig.  53).  These  may  be  so  abun- 
dant as  to  form  considerable  areas. 

What  is  probably  another  disease  causes  the  formation  of 
whitish  spots  having  black  centers.  These  fungi  are  often 
present  at  the  same  time,  and  as  their  histories  are  not  yet 
fully  known  and  their  treatment  is  the  same,  the  two  may  here 
be  considered  together.  They  cause  the  leaves  to  fall  from  the 
bushes  when  the  attack  is  severe,  so  that  the  plants  may  be 
entirely  bare  during  the  latter  part  of  the  summer,  thus  greatly 
weakening  them. 

Treatment.  The  plants  should  be  sprayed  with  a  clear  fungi- 
cide, as  the  ammoniacal  carbonate  of  copper,  to  avoid  staining 
the  fruit.  After  harvesting,  the  Bordeaux  mixture  may  be 
used  to  advantage.  The  first  application  of  the  season  should 
be  made  about  two  weeks  before  the  spots  may  be  expected. 
Since  the  Bordeaux  mixture,  if  properly  prepared,  cannot  injure 
the  plants,  it  may  be  freely  applied. 


286 


The  Spraying  of  Plants. 


INSECT  EMEMIES. 

Borer;  Imported  Currant-borer  (Sesia  \JEger\a\  tipuliformis, 
Linn.).  —  Description.  The  parent  moth,  which  is  about  three- 
quarters  of  an  inch  across  the  expanded  wings,  is  bluish-black 
in  color,  and  has  three  yellow  bars  extending  across  the  abdo- 
men. The  eggs  are  laid  in  the  spring,  and  the  small  white 
larvae  which  soon  appear  gnaw  to  the  pith,  upon  which  they 
feed.  They  pupate  in  the  fall,  but  the  moth  does  not  appear 


FIG.  53.  —  Currant  leaf  spot. 

till  the  following  spring.  The  presence  of  this  borer  materially 
reduces  the  vitality  of  the  cane  in  which  it  feeds,  to  the  injury 
of  the  crop.  Gooseberry  plants  are  also  occasionally  affected. 

Treatment.  The  best  way  to  overcome  the  pest  is  to  watch 
for  weak  canes,  and  when  these  are  found  they  should  be  cut 
off  close  to  the  ground  and  burned. 

Currant-worm;  Currant  Saw-fly;  Gooseberry  Saw-fly;  Im- 
ported Currant- worm  (Nematus  ventricosus  King.).  —  Descrip- 
tion. The  currant-worm  was  imported  from  Europe  probably 
some  years  before  1860.  The  adult  insect  is  a  four-winged 
fly  which  bears  a  certain  resemblance  to  the  common  house- 


Currant.  287 

fly,  except  that  it  is  somewhat  larger  and  has  a  yellowish 
appearance.  These  flies  may  be  seen  in  abundance  in  early 
spring  hovering  about  the  currant  and  gooseberry  bushes,  just 
as  the  first  leaves  are  expanding.  The  small,  white  eggs  are 
laid  on  the  under  side  of  these  leaves,  generally  in  rows  along 
the  larger  veins.  The  eggs  hatch  in  a  week  or  ten  days,  and 
the  worms  immediately  begin  feeding.  The  presence  of  these 
insects  is  frequently  not  noticed  until  fully  one-half  or  two- 
thirds  of  the  leaves  have  been  destroyed ;  this  arises  from  the 
fact  that  the  eggs  are  almost  invariably  laid  upon  the  leaves 
which  are  near  the  ground,  and  also  near  the  center  of  the 
plant.  The  upper  foliage  is  therefore  reserved  till  the  last,  and 
then  when  this  also  is  gone  the  bushes  appear  as  if  suddenly 
defoliated.  The  young  larvae  are  at  first  whitish  in  color ;  they 
soon  become  green,  and  later  they  are  spotted  with  black. 
Before  pupating  they  again  become  green.  There  are  from 
two  to  four  broods  a  year. 

Treatment.  There  is  no  insect  which  is  more  easily  con- 
trolled than  the  currant-worm,  yet  there  is  scarcely  one  wrhich 
is  left  so  undisturbed  in  its  destructive  work.  The  principal 
trouble  is  that  the  pest  is  not  noticed  until  the  currants  are 
about  one-half  grown,  and  at  that  time  much  damage  has 
already  been  done,  and  eggs  are  being  laid  for  a  second  brood. 
If  the  plants  be  thoroughly  sprayed  with  an  arsenite  as  soon  as 
the  first  leaves  are  nearly  grown,  no  injury  will  be  done  to  the 
fruit,  and  practically  all  of  the  first  brood  will  be  killed,  and 
with  it  the  second  one  also.  But  this  first  treatment  must  be 
made  early.  If  later  ones  are  necessary,  hellebore  will  be  found 
an  effectual  remedy,  whether  applied  dry  or  mixed  with  water. 
Such  applications  will  also  free  the  bushes  from  other  leaf, 
eating  insects. 

Four-lined  Leaf-bug ;  Black-lined  Plant-bug ;  Four-striped 
Plant-bug;  Yellow-lined  Currant-bug  (Pcecilocapsus  lineatus, 
Fabr.).  —  Description.  The  mature  insect  (Fig.  54)  is  a  bug 
about  one-third  of  an  inch  long.  Its  back  is  yellow,  but  four 
black  stripes  extend  nearly  its  entire  length,  and  these  have 
given  rise  to  the  many  popular  names  of  the  insect.  Eggs  are 
laid  near  the  tips  of  the  soft  growths  about  a  week  after  the 
appearance  of  the  adults.  The  eggs  do  not  hatch  until  the 
following  spring,  the  young  insects  appearing  during  the  latter 


288 


The  Spraying  of  Plants. 


FIG.  54.  —  Four-lined  leaf-bug  of  currants,  adult. 


part  of  May.     While  young  they  are  bright  red  in  color,  but 
later  more  black  appears  (Fig.  55).     The  adult  insect  may  be 

found  during  June 
and  July.  The  in- 
sects attack  the 
leaves  at  the  tips  of 
the  shoots,  sucking 
out  the  juices.  This 
causes  the  forma- 
tion of  small,brown, 
angular  areas  of 
dead  tissue  (Fig. 
56),  which  at  once 
indicate  the  pres- 
ence of  this  bug  by 
giving  the  leaves  a 
characteristic  spot- 
ted appearance. 

Treatment.  The 
insect  is  extremely  active  during  the  day,  but  in  the  early 
morning  it  may  be 
jarred  from  the  cur- 
rant or  gooseberry 
bushes  and  caught 
in  pans  containing 
kerosene.  Kero- 
sene emulsion,  con- 
taining at  least  9 
per  cent  of  the  oil, 

will  destroy  the  im-  /jRP9g||A%\ 

mature  insects,  but  ^  \&     W^T^i#¥      //  Jfe.     i 

it  must  be  made 
still  stronger  to  kill 
the  adults.  The 
young  insects 
should  be  destroyed 

if  possible.   A  third  Fm  5g  _Four_iine(i  ieaf-bug,  immature  form. 

way    to    overcome 

the  pest,  and  perhaps  the  best  one,  is  to  cut  off  the  tips  of  the 

shoots  which  carry  eggs  and  then  destroy  them. 


Currant. 


289 


Green  Leaf-hopper;  Currant  Leaf-hopper  (Empoa  albopicta, 
Forbes).  —  Description.  These  insects  are  true  bugs.  They 
are  rather  slender,  and  about  an  eighth  of  an  inch  in  length. 
The  color  is  light  green,  almost  white.  The  insects  suck  the 
juices  from  the  under  side  of  the  foliage,  and  this  causes  the 
formation  on  the  upper  surface  of  white  areas  which  invariably 


FIG.  56.  —  Currant  foliage  injured  by  the  four-lined  leaf-bug. 

indicate  the  presence  of  the  pest.  Currants  and  gooseberries 
suffer  most  severely  from  the  first  brood,  during  May  and  June. 
Treatment.  Insecticides  which  kill  by  contact  must  be  used. 
Kerosene  emulsion,  if  directed  towards  the  under  surface  of  the 
leaves,  will  destroy  great  numbers.  Pyrethrum  may  be  used 
successfully,  if  the  plants  are  first  thoroughly  wet,  and  the 
powder  then  freely  dusted  upon  the  foliage,  from  beneath 


290  The  Spraying  of  Plants. 

if  possible.  Tobacco  dust  or  liquor,  or  some  of  the  many  liquid 
commercial  insecticides,  will  prove  of  value  if  properly  applied. 
Whale-oil  soap  has  also  been  recommended. 

DAHLIA. 

Four-lined  Plant-bug.     See  nnder  CURRANT. 
Green  Lettuce- worm.     See  under  LETTUCE. 


EGGPLANT. 
FUNGOUS  DISEASES. 

Anthracnose  (Glceosporium  Melongenea,  E.  &  Hals.).  —  De- 
scription. This  fungus  appears  to  attack  the  fruit  more 
seriously  than  the  other  parts  of  eggplants.  It  causes  the 
formation  of  shallow  pits  in  which  very  small  pink  blotches 
appear.  The  disease  has  as  yet  not  caused  much  loss,  and  no 
attempts  directed  towards  its  treatment  appear  to  have  been 
made.  It  is  probable  that  the  remedies  recommended  for  the 
leaf  spot  will  be  sufficient  for  checking  the  anthracnose. 

Leaf  Spot  (Phyllosticta  hortorum,  Speg.).  —  Description.  When 
this  fungus  attacks  the  foliage  of  eggplants  it  causes  the  leaf 
tissue  to  turn  brown,  and  later  it  becomes  dry  and  brittle. 
These  parts  may  in  a  short  time  fall  from  the  leaf,  forming 
openings  of  varying  sizes.  When  several  of  such  areas  are 
situated  near  each  other,  large  portions  of  the  leaf  may  be 
affected,  and  it  frequently  happens  that  the  plants  lose  nearly 
all  their  foliage  in  this  manner.  The  fruit  appears  to  be 
affected  by  the  same  fungus.  Here  it  appears  as  a  dark  dis- 
coloration which  causes  the  fruit  to  rot,  and  consequently 
renders  it  worthless  for  market. 

Treatment.  If  the  leaf -spot  fungus  is  feared,  the  young 
plants  should  be  sprayed  with  the  Bordeaux  mixture  as  soon 
as  they  have  become  established  in  the  field.  Applications 
should  be  repeated  at  intervals  of  two  or  three  weeks.  When 
the  fruit  is  approaching  maturity,  a  clear  fungicide  should  be 
applied  in  place  of  the  Bordeaux  mixture,  to  avoid  staining  the 
fruit. 

INSECT  ENEMIES. 

Potato-beetle.     See  under  POTATO. 


Elm.  291 

ELM. 
INSECT  ENEMIES. 

Canker-worm.     See  under  APPLE. 

Elm  Span-worm  (Eugonia  subsignaria,  Hiibn.).  —  Description. 
These  insects  hatch  from  eggs  as  soon  as  the  buds  break  in  the 
spring.  The  larvae  are  commonly  known  as  measuring,  or 
span-worms.  They  are  grayish-brown  in  color,  having  a  large, 
red  head,  and  the  last  segment  of  the  body  is  of  the  same 
color.  The  larvae  pupate  about  the  end  of  June,  and  during 
July  and  August  the  mature  insect  appears.  It  is  a  pure  white 
moth,  the  wings  expanding  nearly  one  and  one-half  inches. 

Treatment.  When  possible,  the  affected  trees  should  be 
thoroughly  sprayed  with  Paris  green  used  at  the  rate  of  one 
pound  to  150  gallons  of  water.  This  is  the  best  remedy  against 
all  insects  which  work  on  the  foliage  of  shade  trees,  but  when 
the  trees  are  large  much  difficulty  is  experienced  in  reaching 
all  parts.  See  also  page  195. 

Gipsy  Moth  (Ocneria  dispar,  Linn.).  —  Description.  The 
gipsy  moth  is  found  in  America  only  in  the  immediate  vicinity 
of  Boston.  It  has  there  caused  great  damage,  as  the  larvae  are 
voracious  feeders  and  take  kindly  to  nearly  all  foliage.  The 
eggs  of  the  moth  are  laid  during  July,  August,  and  September, 
generally  near  the  pupa  case  of  the  female.  They  are  deposited 
in  clusters,  and  covered  with  a  thick  layer  of  yellow  hairs.  The 
following  spring  the  young  caterpillars  appear,  and  for  about 
ten  weeks  they  feed  upon  the  foliage  of  most  plants.  When 
grown  they  are  two  inches  or  more  in  length,  and  greenish- 
brown  in  color.  Each  segment  of  the  body  bears  upon  either 
side  a  tuft  of  hairs,  while  along  the  back  there  is  a  double  row 
of  spots,  those  011  the  four  anterior  segments  being  purple  in 
color ;  the  remainder  are  brown.  The  insects  pupate  in  some 
sheltered  spot  on  the  trees,  or  in  neighboring  fences,  etc.  In 
this  state  they  remain  about  ten  days,  when  the  adults  appear. 

Treatment.  The  caterpillars  are  readily  destroyed  by  the 
arsenites,  Paris  green  and  the  arsenate  of  lead  having  been 
most  extensively  used.  The  latter  is  effective  when  used  at  the 
rate  of  two  pounds  to  150  gallons  of  water.  It  is  not  feasible 
in  many  cases  to  make  such  applications,  so  the  insects  are 
destroyed  by  collecting  the  eggs,  and  destroying  them,  and  also 


292  The  Spraying  of  Plants. 

by  trapping  the  larvae  under  bands  of  burlap,  or  some  similar 
material,  bound  about  the  trunks  of  the  trees.1 

Imported  Elm-leaf  beetle;  Elm  Flea-beetle  (Galeruca  xantho- 
melcena,  Schr.).  —  Description.  The  mature  insect  resembles 
the  striped  cucumber-beetle  in  size  and  markings.  The  larva 
is  long,  slender,  and  yellowish-black.  It  has  a  yellow  band  ex- 
tending along  the  back  and  sides.  The  pest  is  most  active  from 
May  till  August,  eating  the  soft  tissues  of  the  leaf,  but  not  the 
veins.  There  are  three  or  four  broods.  Serious  eastward. 

Treatment.  The  arsenites  should  be  used  when  possible, 
spraying  the  tree  thoroughly.  When  large  trees  are  attacked, 
the  insects  may  be  destroyed  by  pouring  hot  water  into  all 
crevices  and  cracks  about  the  base  of  the  tree  and  in  the  imme- 
diate neighborhood.  The  insects  pupate  at  the  surface  of  the 
ground  wherever  a  slight  shelter  can  be  found.  Kerosene 
emulsion  applied  in  the  same  manner  would  also  probably 
prove  effective  in  their  destruction. 

Willow-worm.     See  under  WILLOW. 


GOOSEBERRY. 
FUNGOUS  DISEASES. 

Mildew  (Sphcerotheca  Mors-uvce,  B.  &  C.) .  —  Description.  The 
fungus  attacks  the  foliage  and  young  fruits  soon  after  the  buds 
have  broken.  The  first  appearance  is  the  formation  of  a  cob- 
web-like covering  which  fits  close  to  the  plant.  Later  these 
areas  become  whitish,  and  apparently  sprinkled  with  a  fine 
white  powder.  Affected  leaves  and  shoots  are  checked  in  their 
growth,  and  finally  they  become  dry  and  brown ;  diseased  shoots 
often  branch  freely  (Fig.  57).  The  berries  are  checked  in 
their  growth,  and  generally  drop  from  the  bushes  long  before 
the  time  of  maturity.  They  also  show  the  powdery  covering. 

Treatment.  The  disease  is  caused  by  a  surface  fungus,  and 
the  white  threads  seen  on  the  host-plants  form  the  body  of  the 
parasite.  This  may  be  destroyed  by  applications  of  fungicides, 
especially  some  of  the  copper  compounds,  or  of  the  sulphide  of 
potassium.  Weekly  applications  of  the  latter  have  given  excel- 
lent results.  To  avoid  staining  the  berries,  clear  fungicides 

*  See  the  reports  of  the  Mass.  State  Bd.  of  Agric.  on  the  "  Extermination  of  the 
Gipsy  Moth." 


Gooseberry. 


293 


should  be  used,  although  the  Bordeaux  mixture  may  be  applied 
once  or  twice  early  in  the  season.  The  first  application  should 
be  made  before  the  buds  start  in  the  spring. 

INSECT  ENEMIES. 

Gooseberry  Fruit-worm  (Dakruma  convolutella,  Hiibn.).  —  De- 
scription.   A  pale,  gray  moth  lays  its  eggs  upon  the  young 


FIG.  57.  —  Gooseberry  mildew.    The  shoot  on  the  left  was  sprayed,  the  other  not. 

gooseberries  in  early  spring,  and  the  larvae  which  appear  enter 
the  berries  and  feed  within  them.  This  causes  the  fruit  to 
ripen  prematurely.  When  the  worm  is  full  grown  it  is  about 
three-fourths  of  an  inch  in  length ;  its  head  is  brown,  but  the 
body  is  light  green.  It  leaves  the  berry  and  enters  the  ground, 
passing  the  winter  in  the  pupa  state. 


294  The  Spraying  of  Plants. 

Treatment.  The  affected  berries  should  be  destroyed  when 
discovered.  Poultry  will  aid  in  destroying  the  larvae  before 
they  pupate.  It  has  been  recommended  to  spray  with 
the  sulphur  and  whale-oil  soap  wash  just  before  the  eggs  are 
laid. 

The  other  insects  which  work  upon  gooseberries  have  been 
mentioned  under  CURRANT,  which  see. 


GRAPE. 
FUNGOUS  DISEASES. 

Anthracnose;  Scab;  Bird's-eye  Rot  (Sphaceloma  Ampelinum, 
DeBary).  —  Description.  Anthracnose  is  perhaps  the  most 
formidable  disease  with  which  the  vineyardist  has  to  contend. 
It  does  not  yield  to  the  same  treatment  which  checks  the  other 
fungous  diseases  of  the  grape,  and  even  when  applications  are 
made  which  are  especially  designed  for  its  control,  the  results 
are  not  invariably  satisfactory.  The  vines  should  therefore  be 
watched,  that  the  first  sign  of  the  disease  may  lead  to  its  timely 
treatment. 

The  fungus  causing  anthracnose  attacks  the  fruit,  the  leaves, 
and  the  stems,  in  fact,  all  green  parts  of  the  vine.  It  may 
appear  any  time  during  the  growing  season  of  the  plant,  but 
most  commonly  affects  the  berries  during  the  middle  and  latter 
part  of  summer.  The  name  "  anthracnose  "  is  now  generally 
used  in  this  country  and  in  Europe.  It  is  formed  from  two 
Greek  words  meaning  "  coal "  and  "  disease,"  the  dark  discolora- 
tion of  the  affected  part  suggesting  the  name. 

The  shoots  of  the  grape  are  very  subject  to  the  attacks  of 
the  fungus.  The  first  indication  of  the  trouble  is  a  darkening 
and  sinking  of  small,  oval  areas  which  extend  lengthwise  of 
the  stem.  These  may  be  very  abundant,  giving  the  shoots  a 
speckled  appearance.  The  spots  gradually  enlarge,  and  the 
center  assumes  a  gray  color,  the  edges  still  remaining  dark,  and 
having  a  more  or  less  decided  tinge  of  purple.  After  the 
disease  has  progressed  some  weeks,  the  stem  is  very  seriously 
injured,  and  if  there  have  been  several  points  of  attack,  its 
growth  may  be  entirely  checked  and  the  shoot  destroyed. 
Upon  the  leaf  the  disease  causes  changes  very  similar  to  those 
of  the  stem,  but  there  is  a  reddish-brown  color  in  the  affected 


Grape.  295 

areas,  which  renders  it  more  difficult  to  distinguish  this  disease 
from  some  others.  But  one  peculiarity  of  anthracnose  is  that 
it  generally  attacks  the  veins  of  the  leaves,  as  well  as  the  leaf- 
stems,  and  so  its  identification  is  not  always  difficult.  The 
stems  of  the  clusters  are  also  injured,  and  it  frequently  occurs 
that  a  part  is  completely  girdled,  causing  a  "  ring-around,"  as  it 
is  commonly  called.  The  berries  below  the  ring  do  not  ripen, 
but  remain  green,  and  gradually  shrivel. 

The  berries  of  some  varieties  of  grapes  are  almost  invariably 
affected  to  such  an  extent  as  to  render  them  unfit  for  market. 
The  Yergennes,  Diamond,  Salem,  Agawam,  and  many  others 
are  very  susceptible  to  its  attacks.  The  first  indication  of  the 
presence  of  the  fungus  on  the  berries  is  the  formation  of  dis- 
tinct brown  spots  which  are  practically  circular  in  outline 
(Fig.  58).  The  discolored  part  is  sunken,  and  may  be  bor- 
dered by  a  margin  which  has  a  tinge  of  red  or  purple.  If  a 
berry  is  attacked  in  several  places,  it  becomes  speckled  in 
appearance,  until  the  spots  grow  into  each  other,  forming  con- 
siderable areas  of  irregular  outline.  The  portions  first  diseased 
may  change  to  a  lighter,  or  even  to  a  gray  color,  on  account  of 
the  rupturing  of  the  epidermis  or  outer  skin,  forming  a  hard- 
ened "scab." 

Treatment.  In  Europe,  where  the  fungus  has  long  been 
known,  it  is  the  custom  to  wash  the  vines  and  the  stakes  during 
winter  or  early  spring  with  the  sulphuric  acid  and  sulphate  of 
iron  solution.  The  liquid  is  applied  by  means  of  swabs  or 
brushes.  It  blackens  the  canes,  and  this  is  a  test  of  the 
thoroughness  of  the  work.  See  pages  45,  152. 

If,  after  two  or  three  days,  there  remain  portions  which  are 
unchanged  in  color,  the  vineyard  is  treated  a  second  time,  par- 
ticular attention  being  paid  to  the  parts  omitted  at  the  first 
treatment.  In  addition  to  these  winter  treatments,  the  vines 
are  sprayed  during  the  summer  months  with  the  Bordeaux 
mixture.  As  these  applications  are  made  more  particularly  for 
other  diseases,  the  downy  mildew  and  the  black  rot,  they  will 
not  be  mentioned  here  in  detail. 

European  vineyardists  seem  to  have  perfect  control  of  anthrac- 
nose by  following  the  above  line  of  treatments,  and  the  work 
done  in  America  is  also  promising.  The  cost  of  washing  vines 
and  stakes  in  this  country  scarcely  exceeds  two  dollars  per  acre, 


296 


The  Spraying  of  Plants. 


as  shown  by  actual  trials,  and  marked  benefits  appear  to  have 
followed  the  practice,  even  under  adverse  circumstances.     Vine- 


.  58.  —  Brighton  grapes  affected  with  anthracnose. 


yardists  whose  grapes  are  troubled  with  anthracnose  are  advised 
to  give  the  above  remedy  a  thorough  trial,  for  it  is  the  best  as 
yet  known. 


G-rape.  297 

Black  Rot ;  cnaroon  (Lcesradia  Bidwellii,  V.  &  R. ;  PJioma  uvicola, 
B.  &  C.).  —  Description.  The  name  "black  rot"  has  been  com- 
monly applied  to  this  disease  on  account  of  the  appearance  of 
the  affected  berries,  these  being  of  a  deep  black  color.  But  the 
fungus  causing  the  rotting  of  the  fruit  also  attacks  other  parts 
of  the  plant.  On  the  shoots  it  forms  dark,  oval  areas,  which 
are  slightly  sunken.  The  centers  of  such  spots  are  more  or  less 
thickly  studded  with  very  small  elevations  or  pimples,  these 
being  characteristic  of  the  disease,  and  by  their  aid  the  trouble 
can  in  most  cases  be  identified.  Affected  leaves  turn  to  a  dark, 
reddish-brown  color  at  the  injured  part.  These  portions  are 
generally  found  between  the  larger  veins,  and  not  centered 
upon  them,  as  in  the  case  of  anthracnose.  Their  outlines  are 
generally  rounded. 

To  the  vineyardist  such  attacks  are,  however,  of  slight  im- 
portance as  compared  with  those  which  injure  the  fruit.  There 
is  probably  no  fungous  disease  of  the  grape  which  annually 
causes  greater  losses  than  the  black  rot.  Although  each  berry 
must  be  separately  affected,  since  the  disease  does  not  spread 
from  one  to  the  other  by  means  of  the  stems,  yet  the  conditions 
are  generally  so  favorable  that  a  large  percentage  of  the  crop  is 
annually  lost.  This  applies  particularly  to  southern  vineyards, 
for  in  them  the  disease  is  much  more  virulent  than  at  the 
North.  In  Xew  York,  the  fungus  is  not  generally  serious,  only 
those  regions  being  visited  in  which  the  climate  is  ameliorated 
by  bodies  of  water,  or  by  other  local  conditions.  Localities  in 
which  the  Catawba  ripens  well  may  be  considered  as  subject  to 
the  disease ;  colder  climates  are  comparatively  exempt. 

Grapes  which  show  the  attacks  of  the  black-rot  fungus  are 
generally  nearly  or  quite  full  grown  (Fig.  59).  It  is  therefore 
during  August  and  September  that  the  disease  is  most  to  be 
feared.  If  the  berries  are  still  green  when  the  fungus  gains  an 
entrance,  the  affected  part  turns  a  purplish  brown,  this  color 
gradually  extending  to  the  entire  berry,  which  still  retains  its 
form  and  firmness.  The  part  first  attacked  gradually  becomes 
blackened,  and  characteristic  pimples  appear.  At  the  same 
time  the  berry  shrivels  and  becomes  strongly  ridged,  the  seeds 
projecting  prominently  under  the  drawn  skin  ;  the  entire  berry 
is  then  black,  and  minute  elevations  may  be  seen  scattered 
thickly  over  its  surface,  These  changes  may  take  place  very 


298  The  Spraying  of  Plants. 

rapidly,  so  that  apparently  in  a  few  days  a  crop  may  be  largely 
reduced.  It  seems  to  require  about  a  week  for  the  disease  to 
become  noticeable  after  infection  takes  place,  the  rapidity  of 
the  later  changes  depending  very  largely  upon  the  condition  of 
the  weather.  A  warm,  moist  atmosphere  is  particularly  favor- 
able to  the  development  of  this  fungus. 

Treatment.  Although  the  black  rot  appears  late  in  the  season, 
it  is  always  safe  to  begin  early  in  treating  the  vines.  The  cop- 
per compounds,  especially  the  Bordeaux  mixture,  have  shown 
themselves  to  be  practically  specifics  against  this  disease.  Ap- 
plications should  be  made  before  the  disease  has  appeared.  In 
the  South,  where  the  rot  is  a  regular  visitor,  the  treatments  may 
be  commenced  to  advantage  as  soon  as  the  first  leaves  have 
fully  expanded.  The  second  application  may  be  made  after  the 
vines  have  blossomed,  and  the  third  from  two  to  four  weeks 
later,  depending  upon  the  season.  The  Bordeaux  mixture  may 
be  used  with  safety  up  to  the  time  when  the  berries  are  three- 
fourths  grown,  but  if  used  later  than  this,  there  is  danger  of 
staining  the  clusters  and  reducing  their  market  value.  This 
may  be  partially  avoided  by  reducing  the  strength  of  the  normal 
mixture  one-fourth  or  one-third;  although  not  so  effective  as 
the  stronger  mixture,  the  dilute  form  still  possesses  much  value 
as  a  fungicide,  and  it  may  be  used  to  advantage.  Or  the 
ammoniacal  carbonate  of  copper  may  be  used  in  its  place,  and 
this  is  the  fungicide  very  commonly  employed  when  the  later 
applications  are  made.  If  the  weather  is  favorable  to  the  dis- 
ease, appHcations  should  be  made-about  every  ten  days  after  the 
fruit  is  grown.  Six  or  seven  applications  should  practically 
prevent  the  appearance  of  the  disease,  even  in  badly  infested 
districts. 

In  the  North,  where  the  attacks  are  not  so  severe,  the  treat- 
ments need  not  be  begun  so  early.  If  the  vines  are  thoroughly 
sprayed  about  the  first  of  July,  and  two  additional  applications 
are  made  at  intervals  of  two  or  three  weeks,  little  trouble  need 
be  anticipated  from  black  rot. 

But  everything  depends  upon  the  thoroughness  with  which 
the  work  is  done.  It  was  formerly  supposed  that  to  spray  the 
clusters  was  injurious  to  them ;  but  this  is  a  fallacy.  The  clus- 
ters should  be  treated  as  well  as  the  foliage,  especially  when 
they  are  young,  and  if  the  practice  can  be  continued  without 


FIG.  59.  —  Concord  grape  attacked  by  black  rot 
299 


300  The  Spraying  of  Plants. 

injury  to  the  appearance  of  the  fruit,  so  much  the  better.  It 
is  necessary  that  the  growth  from  the  spores  which  fall  upon 
the  berries  should  be  stopped,  and  this  can  only  be  accomplished 
by  treating  the  clusters,  as  well  as  the  other  parts  of  the  vine. 

The  cost  of  spraying  grape-vines  depends  upon  a  great  many 
factors,  all  of  which  cannot  here  be  discussed  in  detail.  Good 
machinery  is  of  the  greatest  importance,  for  upon  this  depends 
the  quality  of  the  spray.  Reliable  help  will  also  increase  the 
cost  of  the  work,  for  such  men  will  use  more  time  and  more 
material  than  shiftless  workers.  Yet  only  such  labour  should 
be  employed.  The  time  of  the  year  also  affects  the  cost  of  the 
work,  since  early  in  the  year  there  is  much  less  surface  to  be 
covered.  The  character  of  the  season  also  influences  the  total 
outlay  of  the  year,  for  in  some  seasons  twice  as  many  appli- 
cations may  be  required  as  during  others.  A  few  data  regard- 
ing the  spraying  of  grapes  may  be  mentioned,  with  the  assurance 
that  they  will  serve  as  guides  to  those  beginning  the  work. 

Taking  an  average  of  the  applications  made  during  the  entire 
season,  it  may  be  said  that  each  vine  should  receive  approxi- 
mately one  quart  of  liquid  at  each  application.  The  cost  of 
material  and  labor  should  not  much  exceed  one-half  a  cent  per 
vine  for  each  treatment,  whether  the  Bordeaux  mixture  or  the 
ammoniacal  carbonate  of  copper  is  used,  the  latter  being  a  little 
more  expensive.  When  this  small  outlay  is  compared  with 
the  great  benefits  which  so  commonly  result  from  the  work,  it 
is  strange  that  the  practice  is  not  more  generally  followed.  The 
above  figures  refer  to  vines  of  the  Concord  type,  these  making 
a  very  extensive  growth.  For  less  vigorous  varieties  the  cost 
may  be  reduced,  and  the  use  of  some  of  the  machines  now 
manufactured  will  still  further  lessen  the  expense.  This  is 
especially  true  in  the  North,  where  the  black  rot  and  other 
fungous  diseases  of  the  grape  are  not  so  serious  as  southward, 

Downy  Mildew;  Brown  Rot;  Gray  Rot  (Peronospora  mticola, 
DeBary).  —  Description.  This  fungus  attacks  the  stems,  foli- 
age, and  fruit  of  the  grape-vine.  While  it  is  not  generally  so 
serious  as  the  black  rot,  in  the  northern  states  it  is  more  com- 
monly seen,  and  probably  causes  the  loss  of  more  grapes  than 
its  southern  neighbor. 

The  external  characters  of  the  downy  mildew  are  very  dis- 
tinct. On  the  shoots  it  causes  the  formation  of  brown,  slightly 


Gfrape. 


301 


sunken  areas ;  these  may  be  easily  distinguished  from  the  deeper 
and  more  distinctly  marked  spots  caused  by  anthracnose.     But 


FIG.  60.  —  Downy  mildew  upon  grape  foliage. 

it  is  only  in  very  severe  cases  that  the  shoots  are  affected  to  an 
injurious  extent.  It  is  on  the  foliage  and  on  the  fruit  that  the 
greatest  harm  is  done.  The  foliage  (Fig.  60)  first  shows  the 


302  The  Spraying  of  Plants. 

presence  of  the  parasite  by  portions  of  the  leaf  turning  a  lighter 
green  than  that  of  the  normal  tissue.  Later,  these  parts  turn 
yellow,  and  when  the  destruction  of  the  tissue  is  complete,  the 
parts  affected  are  of  a  brown  color.  If  the  under  surface  of 
such  leaves  is  examined,  it  will  be  found  that  there  is  a  frost- 
like  substance  projecting  from  the  discolored  part  of  the  leaf 
after  the  upper  surface  has  begun  to  turn  yellow.  This  appear- 
ance is  due  to  the  formation  of  fungous  threads  which  project 
beyond  the  leaf  surface  and  bear  the  summer  spores  of  the 
parasite.  This  appearance  assists  materially  in  identifying  the 
disease. 

The  fruit  is  also  very  susceptible  to  the  attacks  of  the  downy 
mildew ;  but  when  that  is  affected,  the  vine  does  not  suffer  so 
much  as  the  grower  does.  In  case  of  diseased  foliage,  the  crop 
of  the  next  year,  as  well  as  that  of  the  present,  is  threatened ; 
but  with  diseased  fruit  it  is  only  a  matter  of  the  present  year, 
which  is  all-sufficient  to  make  the  grower  anxious  to  know 
what  can  be  done. 

In  the  southern  states  the  mildew  appears  during  June,  but 
in  the  North  it  is  not  feared  before  July.  The  young  berries 
suffer  very  extensively.  They  are  generally  attacked  before 
they  are  one-half  grown.  The  name  "brown  rot"  has  been 
applied  to  such  fruit  on  account  of  the  brown  color  which  sup- 
plants the  green.  Later,  as  the  fungus  matures,  the  affected 
berries  become  covered  with  a  whitish  powder,  —  the  fruiting 
threads  and  the  spores  of  the  parasite,  —  and  this  gives  the  ber- 
ries a  gray  color,  from  which  has  come  one  of  the  popular  names 
of  the  disease.  Both  forms  of  the  rot  are  nevertheless  caused  by 
the  same  organism,  although  the  external  characters  differ. 

Treatment.  The  downy  mildew  of  grapes  may  attack  the 
vines  throughout  the  growing  season,  and  for  this  reason  it 
is  more  essential  that  applications  be  made  earlier  in  the 
year  than  those  necessary  for  the  control  of  the  black  rot. 
Where  downy  mildew  is  found,  an  application  made  when  the 
shoots  have  grown  from  six  to  ten  inches  is  a  very  important 
one.  The  second  should  be  made  after  the  vines  have  blos- 
somed, and  later  ones  should  succeed  each  other  at  intervals  of 
two  to  four  weeks,  taking  the  same  precautions  against  stain- 
ing the  fruit  as  mentioned  under  BLACK  ROT.  The  treatments 
should  be  preventive  rather  than  curative. 


drape.  303 

Powdery  Mildew  (Uncinula  spiralis,  B.  &  C.).1 — Description. 
The  fungus  causing  the  powdery  mildew  of  the  grape  differs 
from  the  preceding  diseases  in  the  fact  that  it  is  a  surface 
fungus,  the  body  of  the  parasite  not  being  found  in  the  tissues 
of  the  host-plant,  but  upon  the  surface  of  the  green  parts. 
The  vines  are  attacked  throughout  the  growing  season,  but 
contrary  to  the  general  rule,  the  disease  develops  more  abun- 
dantly during  comparatively  dry  weather.  It  is  therefore 
found  over  a  wide  territory,  but  fortunately  it  is  not  as  a 
rule  very  serious. 

Young  shoots  attacked  by  the  powdery  mildew  are  checked 
in  their  growth,  and  if  the  threads  of  the  fungus  are  abun- 
dant, they  impart  to  the  affected  portion  a  grayish-white  color. 
This  color  is  particularly  noticeable  upon  the  leaves  (Fig.  61), 
for  the  fungus  almost  invariably  grows  upon  their  upper  sur- 
face, and  if  allowed  to  develop  unchecked,  large  patches  soon 
become  covered  so  thickly  that  the  green  parts  underneath  can 
no  longer  be  seen.  If  these  patches  are  firmly  rubbed,  the 
white  covering  may  be  removed,  and  the  browning  of  the  parts 
formerly  covered  will  be  seen.  This  is  especially  distinct  when 
the  mildew  has  made  an  energetic  growth.  The  discoloration 
is  due  to  the  small  suckers  which  the  fungus  has  projected  into 
the  leaf  cells  for  the  purpose  of  obtaining  nourishment,  and  the 
greater  the  number  of  these  suckers,  the  more  marked  is  the 
discoloration. 

Affected  berries  show  similar  discolorations,  and  the  whitish 
covering  may  be  removed  as  well.  As  the  berry  grows,  the 
injured  parts  assume  a  brown,  scurfy  covering  which  is  com- 
posed of  dried  epidermis.  This  golden-brown  film  is  very 
commonly  seen  upon  green  grapes ;  it  is  often  cracked  so  that 
the  green  tissue  is  visible.  Such  disfigurements  are,  however, 
not  always  caused  by  the  powdery  mildew,  since  any  cause 
which  destroys  portions  of  the  epidermis  will  be  followed  by 
similar  discolorations. 

Treatment.  The  powdery  mildew  is  not  a  serious  disease, 
and  as  the  body  of  the  fungus  is  not  within  the  host-plant, 
there  is  little  occasion  for  treating  the  vines  until  the  fungus 

1  The  common  surface  mildew  of  European  vines  is  Oidium  Tuckeri.  B.  In 
general  appearance  it  resembles  our  powdery  mildew.  But  it  is  more  easily  con- 
trolled, the  flowers  of  sulphur  having  long  proved  to  be  a  specific. 


304 


The  Spraying  of  Plants. 


has  put  in  an  appearance.  Sulphur  has  been  very  generally 
recommended  for  its  destruction,  the  application  being  made 
either  with  the  dry  powder,  or  after  the  sulphur  has  been 
mixed  with  water.  This  remedy  has  not  given  uniformly  good 
results  out  of  doors,  and  a  safer  plan  is  to  use  some  of  the 
copper  compounds.  Carbonate  of  copper  dissolved  in  ammonia 


FIG.  61.  —  A  fresh  attack  of  powdery  mildew  upon  grape  foliage. 

is  an  excellent  remedy,  and  it  is  easily  applied.     All  parts  of 
the  plants  should  be  treated. 

Rattles;  Shelling.  —  Description.  It  frequently  occurs  that 
grape-vines  drop  their  berries  just  as  the  latter  are  ripening. 
The  outer  extremities  of  the  clusters  are  first  affected.  This 
trouble  is  primarily  caused  by  defective  nutrition  of  the  berries, 
and,  although  to  a  certain  extent  influenced  by  the  action  of 


Grape.  305 

fungi  and  insects,  the  remedial  measures  should  be  directed 
towards  strengthening  the  plant  by  means  of  proper  fertil- 
izers, potash  being  perhaps  the  most  important  element  re- 
quired. See  Cornell  Bulletin,  76,  for  a  full  account  of  the 
trouble. 

Ripe  Rot;  Bitter  Rot  (Glaeosporium  fructigenum,  Berk.). — 
Description.  The  names  given  this  disease  are  suggestive  of 
the  time  in  which  the  berries  are  attacked,  and  what  eifect  the 
fungus  has  upon  the  flavor  of  the  fruit.  The  disease  may 
attack  the  fruit  stems,  and  cause  the  berries  to  wilt  on  account 
of  the  supply  of  nourishment  being  cut  oif.  But  more  com- 
monly the  berries  are  directly  attacked.  Such  fruit  shows  a 
reddish-brown  discoloration  at  the  affected  point,  and  this  color 
soon  extends  over  the  entire  berry.  The  surface  then  becomes 
dotted  with  black  pimples  as  in  the  case  of  black  rot,  but  here 
they  are  not  so  numerous,  and  they  are  also  larger  but  less  ele- 
vated. The  berry  also  shrivels,  but  the  black  color  is  wanting, 
since  those  affected  with  ripe  rot  remain  dark  purplish  brown, 
although  some  assume  a  red  tint.  As  a  rule,  they  fall  to  the 
ground  when  this  stage  is  reached,  while  berries  destroyed  by 
black  rot  remain  upon  the  vine  even  until  the  following  spring. 

Ripe  rot  will  spread  after  the  grapes  have  been  harvested,  and 
care  should  therefore  be  exercised  in  selecting  only  sound  fruit 
when  it  is  to  be  stored.  See  under  APPLE,  page  240. 

Treatment.  The  same  treatment  which  serves  to  check  black 
rot  will  also  control  this  disease,  the  later  treatments  being  of 
special  importance. 

INSECT  ENEMIES. 

Grape-slug;  Grape-sawfly  (Selandria  Vitis,  Harris).  —  Descrip- 
tion. The  adult,  a  small  four-winged  fly,  lays  its  eggs  in 
little  clusters  on  the  under  side  of  the  young  leaves.  These 
eggs  produce  small  yellowish-green  larvae,  which  feed  in  groups, 
beginning  at  the  margin  of  the  leaf  and  eating  inwards  until 
the  leaf  is  destroyed.  Others  are  then  attacked,  and  it  fre- 
quently occurs  that  very  serious  injury  to  the  vineyard  is  done 
by  this  insect.  There  are  two  broods,  the  first  appearing  in 
spring,  and  the  second  in  July  or  August.  The  winter  is  passed 
in  the  pupal  state. 


306  The  Spraying  of  Plants. 

Treatment.  The  larvae  are  easily  destroyed  by  spraying  af- 
fected vines  with  an  insecticide,  such  as  an  arsenite,  hellebore, 
or  kerosene  emulsion. 

Grape-vine  Flea-beetle ;  Steely-bug  (Graptodera  chalybea, 
Illig.). — Description.  This  insect  passes  the  winter  in  the 
adult  form.  As  soon  as  the  buds  of  the  grape  commence  to 
swell  in  the  spring  the  beetles  begin  feeding,  the  centers  of  the 
buds  appearing  to  contain  the  most  coveted  portions.  When  a 
bud  has  been  eaten  in  this  manner  it  is  of  course  useless,  and  in 
cases  of  severe  attacks,  which  sometimes  occur,  the  entire  crop 
of  the  year  may  be  ruined  in  a  short  time.  The  beetles  feed 
for  about  a  month,  when  eggs  are  laid  in  clusters  on  the  under 
side  of  the  leaves.  Small,  dark-brown  larvae  soon  appear,  and 
these  immediately  feed  upon  the  foliage.  In  about  four  weeks 
they  leave  the  vines  and  pupate,  the  adult  beetle  appearing  in 
about  three  weeks.  It  then  continues  feeding  until  fall. 

Treatment.  This  insect  is  very  easily  controlled.  The  vines 
should  be  sprayed  with  Paris  green  when  the  beetles  first  attack 
the  buds,  and  again  when  the  young  larvae  appear.  One  or 
two  applications  made  during  each  of  these  two  periods  will 
practically  clear  a  vineyard  of  the  pest. 

Leaf-hopper ;  Thrip  (Erythroneura  Vitis,  Harris).  —  Descrip- 
tion. This  insect  passes  the  winter  in  the  adult  form.  It  is 
about  an  eighth  of  an  inch  long,  of  a  white  color,  but  marked 
by  three  dark  red  bands.  Eggs  are  laid  in  the  leaves,  the  larvae 
appearing  in  June.  These  miniature  forms  are  without  wings, 
but  otherwise  closely  resemble  the  adult,  except  in  being  smaller. 
They  moult  several  times,  their  white  cast-off  skins  adhering  to 
the  under  surfaces  of  the  leaves  for  some  time.  They  feed 
upon  the  juices  of  the  plant.  Grapes  having  thin  foliage  suffer 
more  from  these  insects  than  do  the  heavier-leaved  varieties. 
The  affected  leaves  appear  indistinctly  spotted  with  white  on 
the  upper  surface,  and  frequently  much  injury  is  done  to  the 
vine. 

Treatment.  The  treatment  of  this  pest  is  unsatisfactory.  If 
the  fallen  foliage  is  gathered  and  destroyed  so  the  insects  can- 
not find  proper  shelter  during  the  winter,  their  number  will  be 
materially  reduced.  The  remedies  suggested  for  the  currant 
leaf-hopper  may  be  of  avail  in  the  vineyard. 


Grreenhouse  Troubles.  307 


GREENHOUSE  PESTS. 

FUNGI  INFESTING  PLANTS. 

There  is  such  an  enormous  variety  of  plants  grown  under 
glass  that  each  cannot  here  be  treated  individually.  Nor  is  this 
necessary,  for  a  few  general  directions  may  be  made  to  cover 
almost  all  cases.  Fungi  as  a  rule  prefer  a  warm,  moist  atmos- 
phere for  their  growth,  and  this  is  generally  found  in  a  green- 
house, as  it  is  essential  to  the  proper  development  of  many 
plants.  But  the  general  opinion  of  gardeners  is  that  even  when 
such  conditions  exist,  mildews  need  not  necessarily  appear.  It 
is  said  that  extremes  of  temperature,  of  humidity,  and  draughts 
of  air  are  conducive  to  disease,  and  common  practice  tends 
strongly  to  support  the  notion.  Such  conditions  should  there- 
fore be  avoided  as  far  as  possible. 

Some  of  the  surface  fungi  found  on  plants  grown  under  glass, 
especially  in  houses  improperly  ventilated,  are  destroyed  by 
spraying  the  foliage  with  clear  water  or  with  some  prepared 
insecticide  or  fungicide,  soapy  mixtures  being  most  commonly 
employed.  Fungi  whicli  cannot  be  disposed  of  in  this  manner 
are  reduced  by  removing  diseased  parts  of  the  host-plant  and 
destroying  them.  This  tends  to  prevent  new  infections,  and  it 
is  a  process  which  well  repays  the  outlay  of  time  and  labor. 

Sulphur  is  probably  the  most  valuable  preventive  of  the  fun- 
gous disease's  which  attack  greenhouse  plants.  It  may  be  used 
in  various  ways.  An  early  method  of  making  applications,  and 
one  still  employed,  is  to  dust  the  plants  with  the  dry  powder. 
This  is  effective  in  destroying  several  surface  mildews.  A  prep- 
aration of  sulphur  formerly  very  generally  employed  is  in 
liquid  form.  It  is  the  Eau  Orison  of  the  French,  and  is  very 
valuable  in  the  treatment  of  diseases  which  may  be  controlled 
by  the  powder.  But  the  most  efficient  method  of  using  sulphur 
is  to  place  it  in  a  warm  situation  so  that  it  will  rapidly  give  off 
its  fumes,  and  still  not  take  fire.  It  may  be  mixed  with  equal 
parts  of  lime  or  some  similar  powder,  and  then  by  the  aid  of 
water,  oil,  or  other  liquid,  it  is  wet  until  a  thin  paste  is  formed. 
This  is  then  smeared  upon  the  heating  surfaces  of  the  house. 
Or  the  sulphur  may  be  evaporated  in  a  sand  bath  over  an  oil 
stove,  but  in  such  cases  extreme  care  must  be  exercised  that 


308  The  Spraying  of  Plants. 

the  material  does  not  take  fire,  for  this  means  instant  death  to 
all  plants  reached  by  the  fumes. 

If,  in  spite  of  the  above  precautions,  fungi  are  still  present 
to  an  injurious  extent,  the  next  plan  to  follow  is  to  apply  some 
of  the  standard  liquid  fungicides  to  the  threatened  plants,  pre- 
ferring those  remedies  which  are  clear  solutions,  for  these  dis- 
figure even  the  most  delicate  colors  to  only  a  very  small  extent. 
If  this  does  not  prove  effectual,  the  plants  should  be  thrown 
away,  and  the  grower  might  do  well  to  try  some  other  business. 

INSECTS  INFESTING  PLANTS. 

The  number  of  different  insects  injurious  to  greenhouse  plants 
is  rather  small,  although  the  number  of  the  individuals  of  each 
kind  may  be  large  enough.  These  creatures  for  the  most  part 
require  different  methods  for  their  extermination,  and  each  of 
the  more  important  will  be  treated  in  detail. 

Aphis;  Green-fly;  Plant  Lice.  —  Description.  These  sucking 
insects  are  too  well  known  to  require  description,  for  they  attack 
nearly  all  greenhouse  plants.  They  reproduce  with  extreme 
rapidity,  and  must  therefore  be  continually  watched.  Affected 
leaves  generally  curl,  the  insects  being  found  on  the  under  side. 
When  the  stems  are  attacked,  frequently  no  external  sign  of 
the  insect's  presence  is  visible  except  the  insect  itself. 

Treatment.  Insecticides  which  kill  by  contact  must  be  em- 
ployed for  destroying  the  aphis.  Kerosene  emulsion,  pyre- 
thrum,  tobacco  water,  etc.,  may  be  used  with  success.  But  the 
most  common  method  of  clearing  a  house  of  these  creatures  is 
to  fumigate  with  tobacco  stems.  A  common  coal  scuttle  will 
answer  the  purpose  well;  when  filled  with  the  stems  it  will 
supply  smoke  sufficient  for  a  house  containing  from  three  thou- 
sand to  five  thousand  cubic  feet.  The  amount  to  use  will  vary 
with  the  tightness  of  the  house  and  the  quality  of  the  stems. 
The  stems  should  be  sufficiently  moist  to  prevent  them  from 
blazing.  They  may  be  ignited  very  easily  with  some  paper  or 
shavings.  If  the  house  is  a  very  tight  one,  it  is  well  to  admit 
air  after  the  fumes  have  been  in  about  an  hour,  but  in  the  ma- 
jority of  establishments  this  point  takes  care  of  itself.  If  only 
few  plants  are  to  be  treated,  they  may  be  placed  singly  under  a 
paper  flour-sack  or  in  a  box,  and  then  smoked,  care  being  taken 
not  to  use  too  much  tobacco.  Some  commercial  preparations  of 


Greenhouse  Pests.  309 

tobacco  are  excellent,  for  they  are  as  efficient  as  the  stems,  and 
are  almost  free  from  smoke  and  leave  no  offensive  odor.  If 
powders  are  preferred  for  destroying  aphis,  pyrethrum  will  be 
found  efficient,  especially  if  the  plants  have  been  wet  previous 
to  the  application  ;  tobacco  dust  will  also  answer  the  same 
purpose. 

Foliage-eating  Insects,  of  which  there  are  many  kinds,  should 
be  treated  by  making  applications  of  such  insecticides  as  Paris 
green,  hellebore,  etc.,  but  the  foliage  of  many  plants  is  easily 
injured  by  the  arsenites,  so  these  should  be  used  cautiously. 
Picking  the  insects  off  by  hand  is  another  means  of  clearing 
the  plants. 

Mealy-bug  (Dactylopius  adonidum,  Linn.).  —  Description. 
Mealy-bugs  are  familiar  to  all  who  have  grown  plants  under 
glass.  They  are  sucking  insects,  and  are  covered  with  a  whitish 
powder  from  which  they  have  received  their  common  name. 
There  is  also  a  considerable  quantity  of  a  cotton-like  material 
present  where  these  insects  have  been  allowed  to  multiply,  and 
thus  they  may  be  easily  recognized.  All  the  green  parts  of 
affected  plants  are  susceptible  to  their  attacks. 

Treatment.  Although  the  mealy-bug  is  one  of  the  oldest  and 
best  known  of  greenhouse  pests,  still  no  very  satisfactory  remedy 
for  it  has  yet  been  discovered.  The  most  practical  plan  is  to 
throw  forcible  streams  of  water  against  them,  so  that  they  may  be 
dislodged.  If  this  practice  is  persisted  in,  it  will  prove  very  effect- 
ive. But  all  plants  will  not  bear  such  treatment,  and  it  is  not 
always  possible  to  throw  the  water,  so  that  the  remedy  has  a 
somewhat  limited  application.  Where  it  cannot  be  employed, 
the  alcoholic  decoction  of  pyrethrum  will  be  found  of  great 
service.  It  should  be  applied  by  means  of  a  small  atomizer, 
and  the  insect  should  be  treated  until  it  is  seen  that  the  liquid 
has  penetrated  the  woolly  covering  and  has  reached  the  body. 
The  latter  then  turns  yellowish-brown.  Comparatively  few 
plants  are  injured  by  this  remedy,  and  its  adoption  is  recom- 
mended. Kerosene  emulsion,  and  commercial  insecticides,  as 
fir-tree  oil,  are  also  of  value.  Plants  should  be  treated  early,  so 
that  the  insect  may  not  obtain  a  foothold. 

Mite;  Verbena  Mite  (Tetranychus  bimaculatus,  Harvey). — 
Description.  This  mite  is  as  yet  not  very  well  known  in  green- 
houses. It  is  very  similar  to  the  red  spider  in  size,  shape,  and 


310  The  Spraying  of  Plants. 

habits,  but  it  is  not  red,  and  it  has  two  dark  spots  at  the  rear 
of  the  back. 

Treatment.  The  mite  is  perhaps  the  most  difficult  to  over- 
come of  all  insects  found  in  the  greenhouse.  Unlike  the  red 
spider,  it  is  but  little  affected  by  a  moist  atmosphere,  or  by 
moisture  upon  the  infested  parts.  If  water  is  forcibly  sprayed 
upon  the  insects  so  that  they  will  be  dislodged,  some  good  will 
result.  But  all  plants  cannot  withstand  this  treatment.  The 
best  method  of  destroying  the  mite  is  probably  to  use  kerosene 
emulsion  containing  from  twenty  to  twenty-five  parts  of  water 
to  one  of  oil,  or  to  apply  Antipest,  Fir-tree  oil,  or  some  other 
good  commercial  insecticide  of  this  nature.  The  insects  are 
most  abundant  on  the  under  surface  of  the  leaves,  and  all 
applications  should  be  carefully  and  forcibly  directed  to  these 
parts.  The  plants  should  be  sprayed  once  or  twice  a  week,  and 
the  foliage  of  some  should  be  washed  or  syringed  an  hour  or 
two  after  the  treatment,  to  prevent  injury  from  the  insecticide. 

Red  Spider  (Tetranychus  telarius,  Linn.).  —  Description.  The 
red  spider  is  a  true  mite,  and  not  a  spider.  It  has  received  the 
name  from  the  fact  that  it  spins  a  web,  and  covers  the  leaves 
and  even  whole  plants  with  an  envelope  of  irregularly  but 
thickly  scattered  silken  threads.  It  sucks  the  juices  of  the 
host-plants,  preferring  the  more  tender  green  parts  for  the 
scene  of  operations,  although  older  foliage  does  not  escape  its 
ravages.  The  red  spider  causes  the  color  of  the  leaf  to  change 
from  green  to  a  grayish-white,  which  shows  very  plainly  upon 
most  plants.  This  whitening  of  the  upper  surface  of  the 
foliage  is  a  certain  indication  of  the  presence  of  a  sucking  in- 
sect, and  generally  this  insect  proves  to  be  either  the  red  spider, 
the  mite,  or  thrips.  The  last,  however,  does  not  form  a  web. 
Such  discoloration  should  be  immediately  investigated,  and  if 
either  of  the  first  are  present,  the  careful  gardener  will  remove 
the  parts  and  take  precautions  to  destroy  any  insects  which 
may  escape  this  process. 

Treatment.  The  red  spider  nourishes  in  a  dry  atmosphere 
and  in  bright,  sunny  places ;  shade  and  moisture  are  unfavor- 
able to  its  development.  Here,  then,  lies  the  secret  of  its  cheap 
and  successful  destruction.  Copious  spraying  of  the  affected 
parts  with  clear  water,  and  the  maintenance  of  a  moist  atmos- 
phere, will  soon  rid  a  house  of  this  insect ;  in  case  such  a  course 


Greenhouse,  Hollyhock.  311 

is  injurious  to  the  plants  grown,  an  occasional  wetting  and  the 
removal  of  infested  leaves  will  be  sufficient  to  subdue  them. 

Insecticides  which  kill  by  contact  may  also  be  used  success- 
fuDy,  but  they  are  not  generally  necessary.  The  fumes  of 
sulphur,  produced  as  described  on  page  175,  are  also  said  to 
have  a  beneficial  action  in  the  destruction  of  the  red  spider, 
as  well  as  of  the  mite. 

Snail;  Slug.  —  Description.  The  foliage  of  plants  grown  in 
moist  situations  under  glass  is  frequently  riddled  or  entirely 
devoured  by  snails.  In  dryer  places  so  much  harm  is  not  done. 
These  animals  feed  mostly  in  the  night,  concealing  themselves 
under  boards  or  other  objects,  or  in  crevices  which  are  dark. 
They  feed  upon  tender  vegetation  of  nearly  all  kinds,  and  may 
cause  irreparable  damage  to  young  seedlings  or  cuttings  in  a 
single  night. 

Treatment.  Large  numbers  of  snails  may  be  caught  by  ex- 
amining the  houses  with  a  light  after  dark.  They  may  also  be 
trapped  by  placing  pieces  of  turnip,  cabbage,  or  other  vegetable 
matter  about  the  houses  in  such  a  manner  that  hiding-places 
may  be  formed.  The  creatures  congregate  under  the  bait,  and 
often  large  numbers  are  caught  in  this  manner.  Salt,  and  also 
lime,  are  said  to  be  distasteful  to  them. 


HOLLYHOCK. 
FUNGOUS  DISEASES. 

Rust  (Puccinia  Malvacearum,  Mont.).  — Description.  During 
May  and  June  the  stems  and  leaves  of  the  hollyhock  may 
become  discolored  by  small  spots  which  at  first  are  yellow,  but 
later  they  become  brown.  These  diseased  parts  are  due  to  the 
presence  of  the  rust  fungus,  a  parasite  which  may  develop  so 
vigorously  and  abundantly  that  the  leaves  of  the  host-plant 
become  dry  and  dead,  as  if  scorched.  The  plants  may  be 
entirely  prevented  from  blossoming,  and  unless  measures  are 
taken  to  check  the  disease,  hollyhocks  may  be  forced  from  cul- 
tivation, as  has  occurred  in  some  parts  of  Europe. 

Treatment.  Hollyhock  rust  may  be  practically  prevented  by 
spraying  the  foliage  with  some  good  fungicide  as  soon  as  the 
leaves  appear  in  the  spring.  The  applications  should  be  re- 
peated frequently  enough  to  keep  the  young  growths  covered. 


312  The  Spraying  of  Plants. 

INSECT  ENEMIES. 

Hollyhock-bug  (Orthotylus  delicatus,  Uhl.). — Description.  These 
bugs,  which  are  bright  green  in  color,  sometimes  attack  holly- 
hocks early  in  the  season  so  vigorously  that  the  plants  wilt,  and 
occasionally  die.  The  insects  suck  the  juices  of  the  plants,  and 
are  undoubtedly  their  worst  insect  enemy. 

Treatment.  Kerosene  emulsion  has  been  successfully  used 
against  the  pest,  and  if  the  applications  are  commenced  as 
soon  as  the  bugs  are  seen,  no  serious  damage  should  result. 


MAPLE. 
FUNGOUS  DISEASES. 

Leaf  Spot  (Phyllosticta  Acericola,  C.  &  E.).  —  Description.  The 
fungus  attacks  the  foliage  of  both  large  and  small  trees,  destroy- 
ing the  green  coloring  matter.  It  appears  in  spring,  causing 
the  formation  of  dark  brown  areas  which  enlarge  very  rapidly. 
Later  the  parts  first  affected  assume  a  lighter,  or  even  a  gray 
color,  although  there  is  much  variation  in  the  appearance  of 
the  disease  upon  different  species  of  maples.  The  patches 
may  finally  extend  over  the  entire  leaf. 

Treatment.  Large  trees  are  treated  with  difficulty,  but  nurs- 
ery stock  may  be  easily  reached.  Plants  should  be  sprayed 
thoroughly  with  the  Bordeaux  mixture  as  soon  as  the  leaves 
appear  in  spring,  and  new  treatments  should  be  made  so  that 
the  young  growths  shall  at  all  times  be  protected.  Destroy- 
ing affected  leaves  may  assist  in  checking  the  disease  upon  the 
shade  trees,  but  spraying  them  by  means  of  proper  machinery 
will  prove  most  satisfactory. 

INSECT  ENEMIES. 

Green-striped  Maple-worm  (Anisota  rubicunda,  Fabr.). — 
Description.  The  adult  insect  is  a  moth  of  a  yellowish-white 
color,  the  shade  varying  in  different  parts  of  the  country.  The 
spread  of  the  wings  is  about  two  and  one-fourth  inches.  The 
insect  passes  the  winter  in  the  pupal  state,  and  in  spring,  when 
the  adult  moths  appear,  large  numbers  of  eggs  are  laid,  gener- 
ally in  clusters  on  the  under  side  of  the  leaves.  The  larvae  are 
striped  longitudinally  with  alternating  bands  of  light  and  dark 


Maple.  313 

green,  while  at  the  posterior  extremity  there  project  two  black 
horns,  each  about  a  quarter  of  an  inch  in  length.  The  larvae 
feed  upon  the  foliage  of  the  trees,  being  particularly  injurious 
in  the  western  states,  where  shade  trees  are  in  certain  years 
entirely  defoliated.  There  are  two  or  three  broods,  depending 
upon  the  latitude. 

Treatment.  The  best  and  most  effective  remedy  is  to  spray 
the  trees  with  Paris  green  or  some  similar  poison,  whenever  such 
a  course  is  practicable.  In  other  cases,  the  larvae  may  be  caught 
in  trenches  about  a  foot  deep  that  are  dug  in  concentric  circles 
about  the  bases  of  the  trees.  The  larvae  wander  from  the  tree 
to  pupate,  and  they  will  collect  in  the  trenches,  where  they  may 
be  easily  destroyed. 

Tussock  Moths  (Orgyia,  sp.).  —  Description.  There  are  several 
species  of  tussock  moths  which  resemble  each  other  very 
closely.  The  caterpillars  when  grown  are  about  an  inch  in 
length ;  the  body  is  yellow  in  color,  and  generally  is  marked 
by  a  narrow,  dark  band  extending  along  the  back.  The  sides 
of  the  body  may  be  similarly  marked.  Upon  the  back,  just 
forward  of  the  center,  may  be  found  four  thick  tufts  of  yellow- 
ish hair,  while  from  the  second  segment  of  the  body  there 
extend  two  long  black  plumes.  A  single  plume  extends  back- 
ward from  the  rear  of  the  body.  The  larvae  hatch  during  May 
from  eggs  which  were  laid  upon  the  silken  cocoons  by  the 
female  during  the  preceding  fall.  In  about  five  weeks  the 
larvae  begin  to  pupate,  the  adults  appearing  a  week  later. 
Only  the  males  possess  wings;  these  expand  nearly  an  inch 
and  a  half.  The  ground  color  is  ashy  gray,  but  several  dark 
lines  cross  the  fore  wings.  As  a  rule  there  are  two  broods. 

Treatment.  These  insects  cause  much  injury  to  shade  trees, 
and  if  unchecked  they  gradually  increase  in  numbers  so  that 
the  trees  are  each  year  defoliated.  The  most  practical  remedy 
appears  to  be  to  collect  the  cocoons  while  the  trees  are  dormant. 
As  the  eggs  are  laid  upon  the  surface  of  the  cocoons  they  may 
be  easily  discovered.  The  cocoons  may  be  found  upon  the 
branches  and  trunks  of  infested  trees,  and  also  upon  fences 
and  in  sheltered  spots  in  the  neighborhood.  The  larvae  are 
also  easily  killed  by  the  arsenites,  although  the  application  of 
the  latter  is  not  always  practicable. 


314  The  Spraying  of  Plants. 

MIGNONETTE. 
FUNGOUS  DISEASES. 

Leaf  Blight;  Mignonette  Disease  (Cercospora  Resedce, 
Feckl.).  —  Description.  "The  disease  first  appears  either  as 
minute  pale  spots  with  brownish  or  yellowish  borders, — 
little  sunken  areas  in  the  succulent  tissue  of  the  leaf,  —  or 
as  reddish  discolorations  which  spread  over  the  leaf  and 
finally  develop  into  these  pale  spots  or  patches.  The  spots 
when  young  are  simply  dead  portions,  uniformly  brown 
throughout ;  but  as  they  become  older  and  larger,  little  black 
specks  appear  in  their  centers,  giving  a  somewhat  granular 
cast.  The  disease  spreads  very  rapidly  over  the  leaves,  the 
dead  areas  grow  larger  and  more  irregular  in  shape,  the 
leaves  commence  to  curl,  wither,  and  hang  limply  against 
the  stems." 1 

Treatment.  Early  and  repeated  sprayings  of  the  young 
plants  with  the  Bordeaux  mixture  or  ammoniacal  carbonate  of 
copper  will  almost  entirely  prevent  the  disease. 

MOSSES   AND   LICHENS. 

It  is  very  rare  that  these  growths  injure  the  cultivated  plants 
upon  which  they  are  found.  But  they  often  lend  an  unkempt 
air  to  a  plantation,  and  for  this  reason,  if  for  no  other,  their 
removal  appears  desirable.  Bordeaux  mixture  has  frequently 
cleaned  fruit  trees  of  these  plants,  and  its  general  use  for  this 
purpose  may  be  recommended.  Alkaline  washes  have  a  similar 
action.  Spanish  moss,  which  in  the  Southern  States  appears  to 
have  an  injurious  action  upon  certain  trees,  may  be  destroyed 
by  spraying  the  tree  with  a  wash  composed  of  eight  cans  of  con- 
centrated lye  dissolved  in  fifty  gallons  of  water.  It  is  possi- 
ble that  strong  fungicides  would  exert  a  similar  influence. 

MUSKMELON. 
FUNGOUS  DISEASES. 

Powdery  Mildew ;  Cucumber  Mildew  (Plasmopara  Cubensis,  B. 
&  C.).  —  Description.  This  disease  has  been  reported  as  having 

i  Fairchild,  Ann.  Repl.  U.  S.  Com.  of  Agric.  1889,  429. 


Muskmelon,  Oats.  31£ 

been  found  upon  squashes,  melons,  cucumbers,  and  pumpkins,  in 
some  cases  inflicting  serious  damage.  It  bears  a  certain  resem- 
blance to  the  downy  mildew  of  grapes  in  its  external  charac- 
ters. Affected  parts  of  the  leaves  turn  yellow,  then  brown, 
while  underneath  these  parts  may  be  found  the  frost-like 
patches  so  characteristic  of  the  downy  mildews.  But  with  the 
cucumber  mildew  the  growth  changes  to  a  color  closely 
approaching  violet.  The  dead  leaf  tissue  soon  becomes 
broken,  and  the  leaf  is  often  entirely  destroyed. 

Treatment.  The  application  of  a  good  fungicide,  as  already 
described  under  downy  mildew  of  the  grape,  should  protect  the 
vines  from  the  fungus. 

INSECT  ENEMIES. 

See  under  CUCUMBER. 

OATS. 

FUNGOUS  DISEASES. 

Loose  Smut  (Ustilago  Arenas,  Jensen).  —  Description.  This 
fungus  causes  the  grains,  and  generally  the  husks  as  well, 
to  be  transformed  into  a  black  mass  in  which  all  the  normal 
tissue  of  the  oat  plant  has  disappeared.  This  powdery  mass 
consists  of  spores.  These  appear  when  the  crop  is  heading, 
and  they  mature  at  blossoming  time.  When  the  crop  is 
harvested  the  spores  have  nearly  all  been  blown  away,  leaving 
a  naked  stalk. 

Treatment.1  "It  has  been  found  that  the  infection  of  the 
plant  takes  place  when  the  seed  is  germinating  and  from  spores 
adhering  to  the  seed  when  planted.  If  these  adhering  spores 
can  be  killed,  a  crop  wholly  free  from  smut  can  be  obtained.2 

"  The  Jensen  or  hot-water  treatment  for  oat  and  wheat  smut.  —  This 
method,  discovered  by  J.  L.  Jensen,  of  Denmark,  in  1887,  con- 
sists in  immersing  the  seed  which  is  supposed  to  be  infected 
with  smut  for  a  few  minutes  in  scalding  water.  The  tempera- 
ture must  be  such  as  to  kill  the  smut  spores,  and  the  immersion 

1  The  remedies  here  mentioned  have  been  taken  from  farmers'  Bull.  No.  5,  of 
the  U.  S.  Dept.  of  Agric.  Dit.  of  Yeg.  Path. 

2  "  There  is  some  good  evidence  to  show  that  fresh  manure  of  herbivorous  animals 
containing  smut  spores  may,  if  applied  at  the  time  of  planting,  infect  the  young 
plants.     It  is  hardly  necessary  to  mention  this  manner  of  infection,  since  almost  no 
American  farmers  manure  grain  fields  in  this  manner.    There  is  no  danger  in  using 
well-rotted  manure." 


316  The  Spraying  of  Plants. 

must  not  be  prolonged  so  that  the  heat  would  injure  the  germi- 
native  power  of  the  seed.  If  the  water  is  at  a  temperature 
of  132|°  F.,  the  spores  will  be  killed,  and  yet  the  immersion, 
if  not  continued  beyond  fifteen  minutes,  will  not  in  the  least 
injure  the  seed.  The  temperature  must  be  allowed  to  vary  but 
little  from  132i°,  in  no  case  rising  higher  than  135°,  or  falling 
below  130°.  To  insure  these  conditions  when  treating  large 
quantities  of  seed,  the  following  suggestions  are  offered : 

"  Provide  two  large  vessels  —  as  two  kettles  over  a  fire,  or 
boilers  on  a  cook-stove,  the  first  containing  warm  water  (say 
110°  to  130°),  the  second  containing  scalding  water  (132£°). 

"  The  first  is  for  the  purpose  of  warming  the  seed  preparatory 
to  dipping  it  into  the  second.  Unless  this  precaution  is  taken 
it  will  be  difficult  to  keep  the  water  in  the  second  vessel  at  a 
proper  temperature. 

"  The  seed  which  is  to  be  treated  must  be  placed,  a  half-bushel 
or  more  at  a  time,  in  a  closed  vessel  that  will  allow  free  entrance 
and  exit  of  water  on  all  sides.  For  this  purpose  a  bushel  basket 
made  of  heavy  wire  could  be  used,  within  which  spread  wire  net- 
ting, say  twelve  meshes  to  the  inch,  or  an  iron  frame  could  be 
made  at  a  trifling  cost,  over  which  the  wire  netting  could  be 
stretched.  This  would  allow  the  water  to  pass  freely  and  yet 
prevent  the  passage  of  the  seed.  A  sack  made  of  loosely  woven 
material  (as  gunny  sack)  could  perhaps  be  used  instead  of  the 
wire  basket.  A  perforated  tin  vessel  is  in  some  respects  prefer- 
able to  any  of  the  above. 

"  Now  dip  the  basket  of  seed  in  the  first  vessel ;  after  a 
moment  lift  it ;  and,  when  the  water  has  for  the  most  part 
escaped,  plunge  it  into  the  water  again,  repeating  the  operation 
several  times.  The  object  of  the  lifting  and  plunging,  to  which 
should  be  added  also  a  rotary  motion,  is  to  bring  every  grain 
in  contact  with  the  hot  water.  Less  than  a  minute  is  required 
for  this  preparatory  treatment,  after  which  plunge  the  basket 
of  seed  into  the  second  vessel.  If  the  thermometer  indicates 
that  the  temperature  of  the  water  is  falling,  pour  in  hot  water 
until  it  is  elevated  to  132^°.  If  it  should  rise  higher  than  132°, 
add  small  quantities  of  cold  water.  This  will  doubtless  be  the 
most  simple  method  of  keeping  the  proper  temperature  and 
requires  only  the  addition  of  two  small  vessels,  one  for  cold 
and  one  for  boiling  water. 


Oats.  317 

"  Steam,  conducted  into  the  second  vessel  by  a  pipe  provided 
with  a  stopcock,  answers  even  better,  both  for  heating  the 
water  and  elevating  the  temperature  from  time  to  time. 

"  The  basket  of  seed  should,  very  shortly  after  its  immer- 
sion, be  lifted  and  then  plunged  and  agitated  in  the  manner 
described  above ;  and  the  operation  should  be  repeated  eight 
or  ten  times  during  the  immersion,  which  should  be  continued 
fifteen  minutes.  In  this  way  every  portion  of  the  seed  will 
be  subjected  to  the  action  of  the  scalding  water.  Immediately 
after  its  removal  dash  cold  water  over  it  or  plunge  it  into  a 
vessel  of  cold  water  and  then  spread  out  to  dry.  Another  por- 
tion can  be  treated  similarly,  and  so  on  until  all  the  seed  has 
been  disinfected.  Before  thoroughly  dry  the  seed  can  be 
sown ;  but  it  may  be  thoroughly  dried  and  stored  if  desired. 

"  The  important  precautions  to  be  taken  are  as  follows : 
(1)  Maintain  the  proper  temperature  of  the  water  (132£°  F.),  in 
no  case  allowing  it  to  rise  higher  than  135°  or  to  fall  below 
130°.  This  will  not  be  difficult  to  do  if  a  reliable  thermometer 
is  used  and  hot  or  cold  water  be  dipped  into  the  vessel  as 
the  falling  or  rising  temperature  demands.  Immersion  fifteen 
minutes  will  not  then  injure  the  seed.  (2)  See  that  the  volume 
of  scalding  water  is  much  greater  (at  least  six  or  eight  times) 
than  that  of  the  seed  treated  at  any  one  time.  (3)  Never  fill 
the  basket  or  sack  containing  the  seed  entirely  full,  but  always 
leave  room  for  the  grain  to  move  about  freely.  (4)  Leave  the 
seed  in  the  second  vessel  of  water  fifteen  minutes. 

"The  hot-water  treatment  for  oats.  —  The  foregoing  method  is 
applicable  to  both  wheat  and  oats.  With  oats  the  following 
slight  modifications  are  probably  advantageous :  (1)  Have  the 
water  in  the  second  vessel  143 J°  F.  and  immerse  the  seed  five 
minutes,  cooling  with  cold  water  afterwards.  Where  large 
amounts  of  seed  are  to  be  treated  this  will  prove  the  most 
speedy  form  of  the  treatment,  but  great  care  must  be  taken  to 
see  that  every  grain  is  thoroughly  wetted.  (2)  Have  the  water 
in  the  second  vessel  at  132|°  F. ;  immerse  the  seed  ten  minutes 
and  do  not  cool  with  cold  water,  but  spread  out  at  once  to  dry. 
This  last  is  no  doubt  the  best  form  of  the  Jensen  treatment  for 
oats,  since  it  requires  a  shorter  time  than  the  regular  method 
and  the  warmth  of  the  grain  aids  it  materially  in  drying. 
Moreover,  experiments  have  shown  that  seed  treated  in  this 


318  The  Spraying  of  Plants. 

way  yields  the  most  grain  and  straw.  Neither  of  these  modifi- 
cations can  be  recommended  for  wheat  without  more  data  than 
we  now  possess. 

"Potassium  sulphide  treatment  for  oats.  —  In  this  treatment  the 
seed  is  left  twenty-four  hours  in  a  one-half  per  cent  solution 
of  potassium  sulphide.  The  published  experiments  seem  to 
show  that  a  weak  solution  of  potassium  sulphide  is  nearly  as 
good  as  the  hot  water.  The  potassium  sulphide  is  cheapest  in 
the  'fused '  condition,  in  which  form  it  costs  about  twenty-five 
cents  a  pound.  One  pound  of  the  sulphide  should  be  dissolved 
in  twenty-four  gallons  of  water.  Place  the  seed  in  a  wooden 
vessel  and  pour  on  the  solution  till  the  seed  is  covered  several 
inches  deep.  Stir  the  solution  before  pouring  it  on  the  grain 
and  thoroughly  mix  the  seed  several  times  before  taking  it  out 
of  the  solution.  The  oats  should  stand  in  the  solution  twenty- 
four  hours,  after  which  they  may  be  spread  out  to  dry.  The 
solution  gradually  loses  its  strength  and  hence  cannot  be  used 
more  than  three  or  four  times  without  being  renewed. 

"It  will  probably  be  best  to  sow  the  seed  as  soon  as  possible 
and  before  it  becomes  thoroughly  dry. 

"  Soaking  the  seed  twelve  hours  in  a  solution  of  twice  the 
strength  will  no  doubt  prove  effectual. 

"  Copper  sulphate  treatment  for  wheat.  —  This  consists  in  im- 
mersing the  seed  in  a  solution  made  by  dissolving  one  pound 
of  commercial  copper  sulphate  in  twenty-four  gallons  of  water 
for  twelve  hours  and  then  putting  the  seed  for  five  or  ten 
minutes  into  lime  water  made  by  slaking  one  pound  of  good 
lime  in  ten  gallons  of  water. 

"  These  treatments  have  all  been  tried  and  have  proved  effec- 
tive. Probably  the  hot  water  is  the  best  for  general  use.  In 
some  parts  of  the  country,  seed  wheat  is  treated  in  strong  solu- 
tions of  copper  sulphate  and  no  lime  is  used.  This  practice  is 
much  inferior,  since  it  injures  the  seed,  while  those  given  here 
prevent  the  smut  completely  and  at  the  same  time  do  not  injure 
the  seed  if  carefully  followed.  In  all  forms  of  seed  treatment 
care  should  be  taken  to  spread  the  grain  out  to  dry  at  once,  and 
by  frequent  stirring  prevent  its  spoiling.  The  treated  seed 
should  be  handled  only  with  clean  tools  and  should  be  put  in 
sacks  disinfected  by  boiling  fifteen  minutes.  If  these  precau- 
tions are  not  taken  the  seed  may  be  infected  again  after  treat/ 


Oats,  Onion.  319 

ment,  especially  in  case  of  stinking  smut  of  wheat.  If  the  seed 
is  to  be  sown  broadcast  it  will  not  have  to  be  so  dry  as  if  it  is 
to  be  drilled.  The  seed  may  be  treated  with  hot  water  a  con- 
siderable time  before  planting  if  dried  carefully,  but  it  is  prob- 
ably better  to  treat  just  before  planting." 

Rusts.  —  The  various  rusts  which  attack  oats,  wheat,  and 
barley  have  not  been  successfully  treated  by  the  use  of  fun- 
gicides. 

ONION. 
FUNGOUS  DISEASES. 

Mildew  ;  Rust  (Peronospora  Schleideniana,  Unger).  —  Descrip- 
tion. Seed  onions,  especially  when  grown  on  low  ground,  ap- 
pear to  be  particularly  affected  by  this  disease.  The  first 
appearance  of  the  trouble  is  the  formation  upon  the  onion  tops 
of  a  grayish  velvety  coating.  The  leaf  wilts,  and  turns  yellow. 
This  occurs  about  the  time  that  the  onions  begin  to  bottom. 
The  fungus  passes  the  winter  by  means  of  spores  which  are 
developed  within  the  tissue  of  the  host-plant. 

Treatment.  Proper  applications  of  the  Bordeaux  mixture,  or 
of  some  other  fungicide,  if  made  early  in  the  season  and  re- 
peated at  intervals  of  two  weeks,  should  keep  the  disease  in 
check.  All  affected  onions  should  be  destroyed. 

Smut  (Urocystis  Cepulce,  Frost).  —  Description.  The  disease 
is  more  severe  upon  dry  land,  as  the  onions  appear  to  be  less 
able  to  outgrow  it.  The  first  leaves  of  the  seedlings  are 
attacked,  dark  spots  scattered  along  their  surfaces  showing  the 
presence  of  the  fungus.  Such  plants  generally  die  before  the 
third  leaf  is  formed.  When  the  disease  appears  upon  older 
plants  the  bulbs  show  dark  ridges  extending  up  and  down 
their  sides,  even  to  the  leaves.  These  ridges  are  mainly  com- 
posed of  a  sooty  powder  consisting  of  the  spores  of  the  fungus. 
It  has  been  estimated  that  a  single  large  onion  may  mature 
a  cubic  inch  of  smut  in  a  single  season.  The  soil  soon  becomes 
filled  with  the  germs  of  the  disease,  and  it  is  almost  impossible 
to  grow  a  sound  crop. 

Treatment.  Affected  soil  should  not  be  planted  to  seed 
onions.  It  appears  probable  that  by  transplanting  onions  the 
disease  may  be  largely  avoided,  since  it  enters  the  young  onions 
before  they  appear  above  ground.  One  ounce  of  a  mixture  of 


320  The  Spraying  of  Plants. 

equal  parts  of  sulphur  and  lime  to  every  fifty  feet  of  drill  has 
been  recommended  as  a  preventive. 

INSECT  ENEMIES. 

Maggot  (Phorbia  Ceparum,  Meigen).  —  Description.  This  in- 
sect closely  resembles  the  Cabbage  Root-maggot  in  appear- 
ance, and  the  methods  of  treatment  are  practically  the  same  for 
the  two  insects.  See  under  CABBAGE. 


FIG.  62.  —Orange  scab. 

ORANGE. 
FUNGOUS  DISEASES. 

Scab  (Cladosporium  sp.).  —  Description.  Orange  leaves 
affected  with  the  scab  first  show  warty-like  elevations,  mostly 
on  the  under  surface  of  the  leaves  (Fig. 62).  These  excrescences 
also  appear  upon  the  young  shoots.  They  are  at  first  light-col- 
ored, but  later  the  tops  turn  nearly  black.  Growing  leaves  and 
shoots  are  distorted  by  the  parasite,  and  they  finally  become 
yellow  and  worthless. 


Orange.  321 

Leaf  Spot  (Colletotrichum  adustum,  Ellis).  —  Description. 
Leaf  spot  attacks  both  wild  and  sweet  oranges.  It  first  pro- 
duces on  the  leaves  light  green  spots  which  are  about  an  eighth 
of  an  inch  in  diameter.  These  enlarge  till  they  are  fully  an 
inch  across,  the  older  portions  becoming  brown  and  studded 
with  small  black  dots.  This  disease  is  not  as  yet  very  serious. 

Treatment.  The  two  diseases  here  mentioned  have  appar- 
ently not  been  thoroughly  treated,  so  that  all  recommendations 
must  be  founded  upon  the  experiences  gained  in  treating  other 
plants.  The  copper  compounds  will  probably  prove  most  effi- 
cient in  controlling  the  diseases,  the  applications  being  com- 
menced a  week  or  two  before  the  troubles  first  appear. 

INSECT  ENEMIES. 

Leaf  Notcher  (Artipus  Floridanus,  Horn).  —  Description.  The 
adult  is  a  small  insect  about  a  quarter  of  an  inch  long;  it  is  of  a 
metallic  greenish-blue  color.  It  feeds  upon  the  foliage  of  the 
trees,  beginning  at  the  edges  of  the  leaves. 

Treatment.  Jarring  the  trees  has  been  recommended,  and 
it  seems  probable  that  applications  of  the  arsenites  would  prove 
effectual  in  destroying  the  pests. 

Mealy-wing  (Aleyrodes  Citri).  —  Description.  These  minute 
white  flies  frequently  appear  in  such  numbers  upon  orange 
foliage  that  the  tree  may  be  considerably  weakened  by  them. 
Related  forms  are  common  in  northern  greenhouses,  and 
plants  are  often  seriously  injured  by  their  work.  In  the  South 
the  insects  generally  pass  the  winter  in  the  larval  stage.  In 
early  spring  they  pupate,  and  the  adults  appear  during  March 
and  April.  Eggs  are  laid  in  abundance  on  the  under  side  of 
the  leaves.  They  soon  hatch,  and  the  larvae,  on  account  of  their 
transparency,  may  be  present  in  swarms,  and  still  pass  unnoticed. 
They  suck  the  juices  from  the  leaves,  and  secrete  a  honey-dew 
upon  which  a  dark  fungus  soon  grows.  There  are  three  gener- 
ations each  year  in  the  South. 

Treatment.  The  insects  do  not  yield  readily  to  treatments  of 
kerosene  emulsion,  but  the  resin  wash  smothers  the  immature 
forms.  Under  glass,  other  species  are  easily  destroyed  by 
tobacco  smoke. 

Mite ;  Leaf-mite ;  Spider ;  California  Spider ;  Red-spotted 
Mite;  Red  Spider  (Tetranychus  Q-maculatus,  Riley).  —  Descrip- 

T 


322  The  Spraying  of  Plants. 

tion.  The  insect  is  pale  green  in  color,  and  is  marked  above  by 
six  small  dark  spots.  It  feeds  upon  the  juices  of  the  plant, 
and  increases  with  such  rapidity  that,  unless  checked,  the  foli- 
age soon  becomes  ruined.  Ten  days  is  the  estimated  time  for 
maturing  the  insect  from  the  egg  when  conditions  are  favorable. 
The  name  "  spider  "  has  been  applied  to  the  mite  on  account  of 
its  habit  of  spinning  a  fine  thread  which  often  entirely  covers 
the  infested  parts. 

Treatment.  The  pest  is  held  in  check  by  abundant  rains, 
showing  that  it  does  not  relish  water  any  more  than  its  relative, 
the  red  spider  of  greenhouses.  It  is  also  easily  destroyed  by 
kerosene  emulsion,  whale-oil  soap,  and  if  the  trees  are  thoroughly 
and  forcibly  sprayed  with  clear  water,  it  will  have  a  decided 
effect  in  clearing  the  foliage  of  the  insect. 

Rust-mite.  —  The  rusty  appearance  of  oranges  is  caused  by  the 
work  of  a  minute  yellow  animal,  a  true  mite.  It  lives  upon  the 
essential  oil  which  is  found  in  all  parts  of  the  orange  tree,  suck- 
ing it  out  by  means  of  a  beak.  On  the  fruit  this  causes  the 
familiar  browning  of  the  orange. 

Treatment.  As  the  eggs,  molting  young,  and  adults  are  found 
upon  the  trees  at  all  seasons  of  the  year,  no  definite  direction 
can  be  given  which  will  apply  to  every  district.  All  applica- 
tions should  be  repeated  at  intervals  of  a  week  or  ten  days,  so 
that  the  young  may  be  destroyed  before  they  mature.  Spraying 
the  trees  with  sulphur  suspended  in  water  is  one  of  the  best 
remedies,  as  the  fumes  are  deadly  to  the  insects.  Whale-oil 
soap  solution,  made  by  dissolving  one  pound  of  the  soap  in  ten 
gallons  of  water,  is  also  effectual.1 

Glover's  Scale ;  Long  Scale ;  Oystershell  Scale  (MytUaspis 
Glover ii,  Packard).  —  Description.  The  eggs  of  this  insect  hatch 
early  in  spring,  the  young  larvae  being  yellowish  purple  in  color. 
These  almost  immediately  begin  to  secrete  a  cotton-like  covering 
which  extends  over  the  entire  body  in  about  a  week.  The  first 
molt  takes  place  about  three  weeks  after  the  eggs  hatch,  and 
the  covering  of  the  insects  from  that  time  on  is  penetrated  with 
difficulty  by  insecticides.  There  are  three  periods  when  the 
newly  hatched  scales  are  most  abundant :  in  March,  in  June  and 
July,  and  in  September  or  October,  and  each  generation  soon 

1  For  detailed  experiments,  made  by  H.  G.  Hubbard,  see  Ann.  Rep.  17.  S.  Com. 
of  Agric.  1884,361. 


Orange.  323 

covers  itself  with  the  long,  yellowish  or  dark  brown  scale  which 
may  be  found  upon  the  leaves  and  branches  of  the  orange. 

Treatment.  The  trees  should  be  sprayed  with  resin  washes, 
kerosene  emulsion,  or  whale-oil  soap  whenever  the  young  insects 
are  seen.  It  is  especially  important  that  this  should  occur  dur- 
ing the  three  periods  above  mentioned,  for  then  the  greatest 
numbers  can  be  destroyed.  The  old  scales  cannot  be  penetrated 
by  any  insecticide  which  does  not  injure  the  foliage. 

San  Jose  Scale  (Aspidiotus perniciosus,  Coinstock).  —  Descrip- 
tion. This  scale  insect  is  undoubtedly  the  most  serious  to  fruit 
trees  of  any  with  which  the  horticulturist  has  to  deal.  It  is 
.probably  a  native  of  Chili,  but  was  imported  into  California, 
and  from  there  it  has  spread  to  the  eastern  states.  It  is  now 
very  irregularly  scattered  throughout  the  East  and  has  already 
shown  that  it  is  capable  of  destroying  not  only  the  orange,  but 
also  most  of  our  other  fruit  trees. 

During  the  winter  the  San  Jose  scale  is  only  about  one-half 
grown,  the  scale  being  less  than  a  sixteenth  of  an  inch  in  diam- 
eter. It  is  nearly  circular,  quite  flat,  but  the  center  has  a  slight 
elevation.  This  is  of  a  dark  color,  while  the  remainder  of  the 
scale  is  gray.  These  immature  forms  begin  sucking  the  juice 
of  the  plant  as  soon  as  growth  commences  in  the  spring.  They 
complete  their  growth  in  about  four  weeks,  and  then  lay  their 
eggs  under  the  scale.  Early  in  June,  in  the  latitude  of  New 
York,  the  young  insects  begin  to  crawl  out  from  under  the  old 
scale.  In  two  or  three  days  they  settle  down,  and  begin  the 
secretion  of  a  scale  which  resembles  that  of  the  parent  form. 
Before  fixing  themselves  they  are  active,  and  so  minute  that 
their  small  yellow  bodies  can  scarcely  be  seen  without  the  aid 
of  a  glass. 

From  the  time  of  the  appearance  of  the  first  generation  in 
spring,  the  young  insects  can  be  seen  almost  continually  through- 
out the  summer  months,  and  until  the  arrival  of  cold  weather  in 
the  fall.  The  number  of  generations  which  appear  in  a  season 
has  not  yet  been  ascertained. 

Treatment.  The  most  effectual  method  of  ridding  plants  of 
this  pest  is  by  treating  them,  while  dormant,  with  hydrocyanic- 
acid  gas.  With  grown  trees,  the  operation  of  covering  an 
entire  plant  with  an  air-tight  tent  is  a  difficult  process,  al- 
though it  has  been  done  successfully  in  the  orange  groves  of 


324  The  Spraying  of  Plants. 

California.  Nursery  stock  may,  however,  be  treated  very 
easily  in  this  manner,  and  when  the  operation  is  finished  there 
need  be  no  doubt  that  all  the  insects  are  destroyed.  In  California 
the  resin  washes  have  been  used  with  success,  care  being  taken 
that  all  parts  of  the  tree  are  reached  by  the  material.  In  the 
eastern  states  these  washes  have  not  proved  to  be  equally 
effective,  a  solution  of  two  pounds  of  whale-oil  soap  to  a  gallon 
of  water  having  given  the  best  results.  Kerosene  emulsion 
may  probably  be  successfully  used  if  made  according  to  the 
Hubbard-Riley  formula,  and  diluted  five  times.  Caustic  soda 
and  caustic  potash  should  also  give  good  results  if  applied 
during  the  winter  months. 

During  the  summer,  if  kerosene  emulsion  is  persistently  used, 
so  that  at  least  the  majority  of  the  young  are  killed,  the  insects 
may  be  gradually  reduced  in  numbers,  although  the  fight  will 
prove  a  hard  one.  Continued  watching  and  thorough  spraying 
must  in  time  exterminate  the  scale  in  an  orchard. 


PANSY. 

FUNGOUS  DISEASES. 

Mildew;  Rust  (Peronospora  Violce,  DeBary).  —  Description. 
Diseased  leaves  show  the  presence  of  this  fungus  by  turning 
brown  at  the  affected  places.  The  disease  as  yet  does  not 
appear  to  be  well  understood. 

Treatment.  Proper  culture  and  the  application  of  fungicides 
are  to  be  recommended. 

PARSLEY. 
INSECT  ENEMIES. 

Parsley-worm ;  Celery-caterpillar  (Papilio  Asterias,  Cramer). 
—  Description.  The  mature  butterfly  is  black,  but  it  has  rows 
of  yellow  and  blue  spots  upon  the  wings.  These  expand  nearly 
four  inches,  and  the  adult  is  one  of  the  most  handsome  of  our 
summer  butterflies.  The  eggs  are  laid  upon  the  leaves  of 
parsley,  parsnip,  celery,  carrot,  and  many  related  plants.  The 
young  caterpillar,  appearing  in  Jane,  is  at  first  black,  but  as 
it  increases  in  size  the  color  becomes  greenish.  About  the 
middle  of  July,  when  full  grown,  the  larva  is  about  an  inch 


Parsley,  Pea.  325 

and  a  half  long,  the  ground  color  being  pale  green,  but  the 
sides  of  the  body  are  marked  with  a  series  of  yellow  and  black 
markings.  When  disturbed  it  projects  two  yellow  horns  from 
the  back  of  the  head ;  these  emit  a  disagreeable  odor,  and 
doubtless  serve  as  organs  of  defense.  It  soon  seeks  a  sheltered 
spot,  and  there  spins  its  cocoon.  In  about  two  weeks  the  adult 
insect  again  appears.  Eggs  are  laid,  and  the  larvae  become  full 
grown  and  pupate  late  in  September  or  early  in  October.  The 
winter  is  passed  in  this  condition,  the  mature  insect  appearing 
the  following  spring. 

Treatment.  These  insects  are  rarely  present  in  sufficient 
numbers  to  cause  much  injury.  If  their  destruction  is  at- 
tempted, the  arsenites  will  be  found  very  efficient,  but  they 
should  be  applied  only  to  those  plants  whose  foliage  is  not 
used.  Hellebore,  or  pyrethrum,  is  safer  and  almost  as  effective, 
and  these  materials  should  be  applied  to  celery,  parsley,  and 
other  plants  whose  treated  parts  are  used  as  food. 


PARSNIP. 

INSECT  ENEMIES. 

Parsley-worm.     See  under  PARSLEY. 

Web-worm  (Depressaria  heracliana,  De  Geer.)  —  Description. 
The  moths  probably  hibernate  during  the  winter,  laying  their 
eggs  early  in  spring.  The  larvae  appear  in  June.  They  feed 
upon  the  green  parts  of  the  parsnip,  and  protect  themselves  by 
means  of  a  web.  The  flower  cluster  is  particularly  affected. 
This  insect  is  comparatively  rare. 

Treatment.  One  or  two  applications  of  an  arsenite  should  be 
sufficient  to  protect  the  plants,  since  the  insect  appears  to  have 
out  one  brood  each  year.  The  treatments  should  be  made  as 
soon  as  the  larvae  are  seen  in  the  spring.  The  insects  pupate  in 
the  stems  of  the  parsnip,  and  the  destruction  of  these  stems 
late  in  July  would  materially  reduce  the  number  of  the  insects. 


PEA. 

FUNGOUS  DISEASES. 

Mildew  (Erysiphe  Martii,  Lev.).  —  Description.    This  disease 
generally  appears  late  in  summer,  or  during  the  autumn  months. 


326  The  Spraying  of  Plants. 

It  covers  the  foliage  with  a  white,  downy  layer,  which  almost 
entirely  obscures  the  green  color  of  the  leaves  and  stems. 
Later,  small  black  dots  appear,  these  being  the  fruiting  bodies 
of  the  fungus. 

Treatment.  The  disease  could  undoubtedly  be  easily  checked 
by  means  of  the  cop  per"  sprays;  but  the  foliage  of  these  plants 
is  of  such  a  character  that  liquids  do  not  readily  adhere.  Soap 
will  assist  in  overcoming  this  difficulty  if  it  is  added  to  the 
liquids.  Another  line  of  treatment  which  might  be  followed 
by  good  results  is  to  apply  powders  to  the  vines  while  they 
are  wet  with  dew.  Fostite  should  prove  of  value  for  this  pur- 
pose. 

Rust.  —  This  is  the  same  disease  which  has  been  discussed 
under  BEAN.  It  is  rarely  serious. 

INSECT  ENEMIES. 

Weevil;  Pea-bug  (Bruchus  Pm,  Linn.).  —  Description.  The 
adult  is  a  dirty-black  beetle  having  white  markings  on  the  wing 
covers,  and  a  T-shaped  mark  of  the  same  color  at  the  extremity 
of  the  abdomen.  The  insect  is  scarcely  three-sixteenths  of  an 
inch  long.  The  winter  is  generally  passed  in  the  adult  stage, 
the  beetles  mostly  appearing  in  the  spring.  Eggs  are  laid  while 
the  young  pods  are  forming,  and  the  larvae  enter  the  growing 
peas,  upon  which  they  feed,  rarely  injuring  the  germ,  how- 
ever, although  the  seed  is  considerably  weakened.  The  insects 
pupate  within  the  peas,  and  soon  afterward  the  adult  appears, 
although  it  does  not  leave  the  peas,  as  a  rule,  until  the  following 
spring. 

Treatment.  No  practicable  method  has  yet  been  found  by 
means  of  which  the  beetle  can  be  prevented  from  laying  its 
eggs  in  the  young  pods.  The  practice  commonly  followed  is  to 
treat  the  peas,  after  harvesting,  with  the  bisulphide  of  carbon. 
Two  or  three  treatments  at  intervals  of  three  or  four  weeks 
will  be  found  sufficient  to  exterminate  the  pest.  Another 
method  of  destroying  the  insects  is  to  subject  the  peas  to  a 
temperature  of  145°  F.  for  about  an  hour.  If  this  is  done  as 
soon  as  the  peas  are  ripe,  the  larva?,  which  are  then  practically 
grown,  will  succumb,  and  the  germinating  qualities  of  the  seed 
will  not  be  injured.  The  bean-weevil  may  be  successfully 
treated  in  the  same  manner. 


Peach. 


327 


FUNGOUS  DISEASES. 


PEACH. 


Black  Spot  (Cladosporium  carpophilum,  Thm.).  —  Description. 
This  surface  fungus  is  generally  more  severe  upon  late  varie- 
ties, Hill's  Chili  being  especially  susceptible  to  its  attack.  It 
forms  small  dusky-brown  or  black  spots  upon  the  side  of  the 
fruit  (Fig.  63),  and  although  the  spots  scarcely  exceed  one- 


FIG.  63.  — Black  spot  of  peach. 

eighth  of  an  inch  in  diameter,  when  several  run  together,  large 
areas  of  the  peach  may  be  affected  (Figs.  64,  65).  In  such 
cases,  all  growth  of  the  diseased  portion  is  stopped,  and  fre- 
quently the  flesh  cracks  down  to  the  pit.  As  a  rule,  the  disease 
is  not  very  troublesome. 

Treatment.  Spray  the  trees  with  the  Bordeaux  mixture,  be- 
ginning the  treatments  early  in  July.  The  mixture  should  not 
be  made  stronger  than  one  pound  copper  sulphate  to  ten  gallons 
of  the  liquid,  and  an  abundance  of  lime  should  be  added,  other- 


328 


The  Spraying  of  Plants. 


wise  the  foliage  may  be  seriously  injured.  Two  applications 
may  be  required  after  the  first  of  August.  For  these,  a  clear 
fungicide,  such  as  the  ammoniacal  carbonate  of  copper,  should 
be  used,  but  there  is  again  danger  of  burning  the  foliage.  For 
this  reason,  the  solution  should  not  be  made  stronger  than  an 
ounce  to  twelve  gallons  of  water.  Some  injury  may  result  even 
from  this  dilute  preparation,  but  it  will  be  so  slight  that  no 
serious  loss  need  be  feared.  Powders  have  proved  unsatisfac- 
tory in  the  treatment  of  peaches,  as  the  leaves  are  so  smooth 
that  but  little  of  the  material  adheres  to  them.1 


FIG.  64.  —  Fruit  severely  attacked  by 
black  spot. 


FIG.  65.  —  Same  as  Fig.  64, 
another  view. 


Brown  Rot;  Fruit  Rot;  Twig  Blight  (Monilia  fructigena, 
Pers.).  —  Description.  Brown  rot  is  probably  the  most  serious 
fungous  disease  with  which  peach  growers  are  obliged  to  con- 

1  Peach  trees  should  at  all  times  be  treated  cautiously.  At  a  meeting  of  the 
A.  A.  A.  S.  held  at  Springfield,  Mass.,  Aug.  2T,  1895,  "P.  H.  Rolfs  read  a  paper 
upon  '  Some  unexpected  results  from  spraying  peach  orchards.'  He  said  :  In  spray- 
ing peach  orchards  with  the  resin  wash  advised  by  the  division  of  entomology,  it 
was  found  that  the  insecticide  was  excellent  when  used  during  dry  weather.  When 
the  wash  was  used  late  in  the  year  and  early  in  the  spring,  it  was  liable  to  destroy 
the  fruit  buds.  In  no  case  did  the  insecticide  affect  the  leaf  buds.  The  experiments 
show  that  the  insecticide  advised  for  winter  use  should  not  be  used  in  winter  in 
Florida,  but  may  be  used  in  September  and  October."  —  Springfield  Republican, 
Aug.  28,  1895,  4.  See,  also,  Bull,  xviii.,  Cornell  Exp.  Sla. 


Peach.  329 

tend.  The  disease  is  more  severe  upon  early  varieties,  and  in 
the  middle  Atlantic  states  the  fungus  is  extremely  prevalent 
and  serious.  It  causes  the  rotting  of  the  fruit  about  the  time 
the  period  of  ripening  begins.  It  increases  rapidly  in  warm, 
moist  weather,  and  peaches  which  touch  each  other  are  among 
the  first  to  suffer  from  the  disease.  This  is  mainly  due  to  the 
fact  that  a  certain  amount  of  moisture  is  retained  at  the  point 
of  contact,  and  with  such  favorable  conditions  the  fungus 
easily  succeeds  in  gaining  an  entrance.  Cherries  and  plums 
also  suffer  from  the  disease,  and  in  the  same  manner;  the 
sweet,  soft-fleshed  varieties  of  cherries  are  especially  susceptible. 
The  affected  fruit  turns  brown  and  appears  as  if  decayed ;  it 
then  becomes  covered  with  an  ash-colored  coating  which  consists 
of  myriads  of  spores,  each  one  capable  of  spreading  the  disease. 
The  fungus  also  attacks  the  small  twigs,  causing  their  death 
(Fig.  66).  It  is  no  uncommon  sight  to  see  dried  peaches, 
plums,  or  cherries  attached  to  the  branches  upon  which  they 
grew,  the  latter  having  been  destroyed  by  the  disease  as  well 
as  the  fruit.  It  also  appears  certain  that  the  blossoms  may  be 
affected  and  ruined,  so  that  no  fruit  will  set.  This  disease, 
therefore,  should  be  closely  watched  and  thoroughly  controlled. 

Treatment.  The  treatment  here  described  applies  practically 
also  to  plums ;  but  cherries  cannot  be  treated  so  often,  as  the 
fruit  matures  earlier.  (1)  The  first  application  should  be 
made,  in  badly  infested  districts,  just  before  the  buds  begin  to 
swell ;  at  this  time  spray  with  a  simple  solution  of  copper 
sulphate,  using  one  pound  to  twenty-five  gallons  of  water. 
(2)  While  the  buds  are  swelling,  spray  with  the  Bordeaux  mix- 
ture. (3)  Repeat  the  second  when  the  fruit  has  set.  (4)  When 
the  fruit  is  grown,  spray  with  the  ammoniacal  carbonate  of  cop- 
per, using  one  ounce  of  copper  carbonate  to  twelve  gallons  of 
water.  (5)  Repeat  the  fourth  application  at  intervals  of  six  or 
eight  days  until  the  fruit  is  harvested.  It  is  only  in  very  few 
localities  that  such  measures  need  be  adopted ;  in  the  majority 
of  cases  the  third  and  the  fifth  recommendations  will  suffice. 

Curl ;  Leaf  Curl ;  Trenching  (Ezoascus  deformans,  Fuckl.) .  — 
Description.  The  name  "curl"  has  been  given  to  this  disease 
on  account  of  the  appearance  of  the  affected  leaves.  As  soon  as 
the  first  leaves  have  become  grown,  they  frequently  show  a 
curled  or  puckered  appearance  (Fig.  67) ;  the  ridges  may 


330 


The  Spraying  of  Plants. 


FIG.  66.  —  Brown  rot  of  peaches. 

extend  across  the  leaves  or  in  a  longitudinal  direction.  They 
appear  as  if  puffed  up,  and  the  normal  green  color  is  replaced 
by  shades  of  yellow  or  red.  Such  foliage  generally  falls  from 
the  trees  before  July,  when  another  set  of  leaves  is  produced. 
The  mycelium  of  the  fungus  appears  to  live  through  the  winter 


Peach. 


331 


upon  the  buds  and  twigs,  for  when  buds  are  taken  from  dis- 
eased trees  and  inserted  in  nursery  stock  the  resulting  shoots 
generally  show  the  dis- 
ease, although  there 
was  no  apparent  infec- 
tion when  the  budding 
was  performed. 

Treatment.  Some 
think  to  have  con- 
trolled the  disease  by 
spraying  thoroughly 
with  the  copper  sul- 
phate solution  before 
the  buds  break,  and 
following  this,  after 
the  trees  have  blos- 
somed, with  applica- 
tions of  the  Bordeaux 
mixture  at  intervals  of 
about  two  weeks  until 
July  first.  Burning  af- 
fected leaves  and  giv- 
ing good  cultivation 
may  also  decrease  the 
severity  of  the  trouble. 

Leaf^Rust.     See  under  PLUM. 

Mildew    (Podosphcera   Oxycanthce,  De- 
Bary).  —  Description.     Early  in  the  sea- 
son, before    the    peaches    are    one-half 
grown,  they  are  occasionally  attacked  by 
a  mildew  which  produces  white,  powdery 
patches  upon  their  surface    (Fig.    68). 
These  may  be  very  small,  or  they  may 
enlarge  until  they  are  fully  half  an  inch 
in  diameter.     As   the   season   advances 
these  parts  become  brown  and  hard,  some- 
times causing  the  peach  to  crack.     The 
ldew'      foliage  is  also  attacked  by  this  fungus; 
here  it  produces  a  thick  covering  of  white  mycelium  which 
entirely  obscures  the  green  color  underneath. 


FIG.  67.  —  Peach  curl. 


332  The  Spraying  of  Plants. 

Treatment.  It  is  probable  that  the  disease  can  be  checked 
by  spraying  the  trees  with  the  Bordeaux  mixture  as  soon  as  the 
fruit  has  set,  and  following  this  at  intervals  of  two  weeks  by 
two  treatments  of  one  ounce  of  the  carbonate  of  copper  dissolved 
in  ammonia  and  diluted  with  twelve  gallons  of  water. 

Rosette.  —  This  disease  causes  the  growth  of  affected  trees  to 
become  compressed  and  bunched  in  the  form  of  a  rosette.  The 
causes  as  well  as  the  remedies  are  unknown.  The  disease  is 
found  only  in  the  southern  states.  It  is  contagious,  and  affected 
trees  should  be  destroyed. 

Yellows.  —  Peach  yellows  is  a  disease  which  has  so  far  baffled 
all  researches  as  to  its  cause  or  the  methods  of  curing  affected 
trees.  The  trees  first  ripen  their  fruit  prematurely,  the  peaches 
possessing  distinct  red  streaks  extending  from  the  surface  towards 
the  pit.  The  following  years  the  new  growth  is  generally  tufted, 
and  branched  shoots  are  produced  from  wood  that  is  more  than 
two  years  old.  Such  growths  have  narrow,  horizontal  leaves, 
which  are  yellowish  in  color.  The  disease  is  contagious,  and 
affected  trees  should  be  burned  as  soon  as  the  disease  is  dis- 
covered. No  cure  is  known. 

INSECT  ENEMIES. 

Black  Peach-aphis  (Aphis  Persicce-niger,  Smith).  —  Descrip- 
tion. These  plant  lice  are  shining  black  in  color,  one  form  hav- 
ing wings,  the  other  possessing  none.  They  feed  upon  the  juices 
of  the  trees,  and  may  be  found  upon  the  leaves,  stems,  and  roots. 
They  reproduce  in  the  characteristic  manner  of  plant  lice. 

Treatment.  The  insects  found  above  ground  may  be  de- 
stroyed by  kerosene  emulsion  diluted  fifteen  or  twenty  times,  or 
by  tobacco  water.  Those  found  upon  the  roots  are  more  diffi- 
cult to  destroy.  Tobacco  stems  or  dust  may  be  dug  about  the 
affected  parts;  or  the  roots  may  be  exposed,  and  water  having 
a  temperature  of  130°  F.  poured  upon  them.  Another  remedy 
which  should  give  excellent  results  is  to  inject  bisulphide  of 
carbon  about  the  roots,  using  about  a  teaspoonful  to  every 
square  foot  of  soil.  The  roots  of  young  trees  may  be  dipped 
in  hot  water  or  in  kerosene  emulsion  before  setting  them  in 
their  permanent  positions. 

Borers.     See  under  APPLE. 

Plum  Curculio.     See  under  PLUM. 


Pear. 


333 


PEAR. 
FUNGOUS  DISEASES. 

Leaf  Blight;  Fruit  Spot  (Entomosporium  maculatum,  Lev.). — 
Description.     The  leaves,  stems,  and  fruit  of  the  pear  are  sub- 


FIG.  69.  —  Pear  leaf  blight. 

ject  to  the  attacks  of  the  leaf  blight  fungus.  Quince  trees  suffer 
in  the  same  manner.  The  disease  appears  as  soon  as  the  first 
leaves  are  developed,  or,  if  the  weather  is  dry,  it  may  not  cause 
any  injury  until  midsummer.  The  leaves  become  dotted  with 
reddish-brown  spots  which  gradually  increase  in  size,  coalesce, 


334 


The  Spraying  of  Plants. 


and  eventually  destroy  large  areas  (Fig.  69).  The  leaves  finally 
fall  to  the  ground,  and  if  the  fungus  is  very  prevalent  the  trees 
may  be  entirely  defoliated.  Upon  the  stems  the  affected  parts 
appear  black  and  dead.  The  fruit  first  shows  reddish  spots 
which  later  turn  dark  (Fig.  70).  If  the  pears  are  attacked 
while  small,  the  diseased  parts  grow  but  slowly,  the  tissues 
become  hard  and  corky,  and  the  result  is  an  irregular  fruit, 
generally  cracked  upoii  the  dwarfed  side,  and  more  or  less 
marked  by  isolated  spots  which  appeared  after  the  first  seri- 
ous infection.  Quinces  suffer  in  the  same  manner,  but  the 


FIG.  70.  —The  fruit  spot  of  pears. 

foliage  frequently  turns  yellow  before  falling  to  the  ground, 
and  the  affected  fruit  is  mottled  with  black  spots  less  than  an 
eighth  of  an  inch  in  diameter,  when  late  infections  have  taken 
place.  This  fungus  is  probably  the  most  serious  of  those  which 
work  upon  these  fruits,  but  fortunately  it  may  be  controlled 
with  comparative  ease. 

There  is  a  bacterial  disease  which  is  frequently  mistaken  for 
the  leaf  blight,  but  it  is  entirely  distinct.  It  is  commonly  known 
as  "  fire  blight "  or  "  twig  blight."  It  is  very  serious  upon  pears 
and  quinces,  and  also  frequently  attacks  some  varieties  of  apples. 
It  causes  the  foliage  to  turn  to  a  uniform  brown,  the  change 
taking  place  sometimes  in  two  or  three  days.  The  leaves  do  not 


Pear.  335 

fall  from  the  trees  but  remain  upon  the  branches,  giving  the 
parts  the  appearance  of  having  been  scorched  by  fire.  The 
bark  of  affected  stems  becomes  brown  and  sunken.  The  bac- 
terium enters  the  tree  through  the  blossoms  and  also  through  the 
growing  tips.  There  is  no  known  remedy,  the  only  method  of 
checking  the  malady  being  to  cut  out  affected  parts  and  to 
burn  them  as  fast  as  they  appear. 

Treatment.  The  leaf  spot  of  pear  and  quince  may  be  pre- 
vented by  spraying  the  trees  with  the  Bordeaux  mixture  as 
soon  as  the  first  leaves  have  developed.  The  application  should 
be  repeated  at  intervals  of  two  to  four  weeks,  more  treatments 
being  made  during  moist  weather,  until  the  first  of  August. 
Later  treatments  will  rarely  be  required.  In  case  they  should 
appear  to  be  necessary,  the  ammoniacal  carbonate  of  copper, 
diluted  as  for  peaches,  should  be  applied.  Other  clear  fungi- 
cides will  answer  the  same  purpose  for  the  late  treatments. 

Rust.     See  under  APPLE. 

Scab.     See  under  APPLE. 

INSECT  ENEMIES. 

Borers.     See  under  APPLE. 

Bud-moth.     See  under  APPLE. 

Cigar-case  Bearer.     See  under  APPLE. 

Codlin-moth.     See  under  APPLE. 

Curculio.     See  under  PLUM. 

Midge  (Diplosis  pyrivora,  Riley).  —  Description.  The  mature 
insect  is  a  small  two-winged  fly  or  gnat.  It  appears  in  early 
spring,  the  winter  having  been  passed  in  the  pupal  stage,  and 
lays  its  eggs  in  the  young  pear  blossoms  even  before  these  are 
fully  opened.  The  eggs  hatch  quickly,  and  the  larvae  immedi- 
ately bore  into  the  young  fruit,  which  they  pierce  in  all  direc- 
tions. The  fruit  becomes  swollen  and  misshapen,  and  eventually 
drops  from  the  trees.  Before  this  takes  place  the  pears  crack 
open  in  wet  weather,  and  thus  allow  the  escape  of  the  midge 
larvae.  The  larvae  are  less  than  three-sixteenths  of  an  inch  in 
length;  they  are  pale  yellow  in  color,  and  have  a  very  smooth 
skin.  They  enter  the  ground  early  in  June  and  there  pupate; 
the  mature  insect  appears  the  following  spring. 

Treatment.  The  pear-midge  is  exceedingly  difficult  to  control. 
It  cannot  be  reached  by  insecticides  while  in  the  pears,  and  after 


336  The.  Spraying  of  Plants. 

it  has  pupated  it  is  also  well  protected.  If  the  pears  are  not 
allowed  to  set,  the  larvae  will  be  unable  to  develop,  and  the 
recommendation  has  therefore  been  made  that  the  trees  be 
sprayed  while  in  blossom  and  all  the  fruit  prevented  from 
setting.  This  might  be  accomplished  by  using  an  arsenical 
spray,  as  white  arsenic,  but  no  experiments  appear  to  have 
been  made  to  settle  the  point.  Picking  the  affected  fruit  before 
the  larvae  enter  the  ground  has  also  been  suggested,  as  well  as 
thorough  cultivation  to  destroy  the  pupae.  Thorough  applica- 
tion of  kerosene  upon  the  surface  of  the  soil  would  also  destroy 
many  of  the  larvae  before  they  pupate.  Professor  Smith  has 


FIG.  71.  —  Pear  leaf  blister. 

said  that  heavy  fertilizing  applications  of  kainite,  if  made 
early  in  July,  will  materially  reduce  the  numbers  of  this  insect. 
Pear  Leaf  Blister  (Phytoptus  Pyri,  Scheuten).  —  Description. 
The  animal  causing  the  reddish  blisters  so  commonly  seen 
upon  pear  leaves  early  in  the  season  (Fig.  71)  is  a  true  mite 
(Fig.  72).  It  passes  the  winter  under  the  outer  scales  of  the 
buds,  and  as  soon  as  warm  weather  starts  the  trees  into  growth 
it  abandons  its  winter  quarters  and  begins  to  feed  upon  the 
juices  of  the  young  foliage.  The  insect  enters  the  leaves,  where 
it  is  entirely  protected  from  all  applications  of  insecticides. 
The  presence  of  this  pest  causes  the  formation  of  small  swell- 
ings which  are  dull  red  early  in  the  season,  but  later  they  turn 


Pear. 


337 


green,  and  about  the  middle  of  June  they  appear  as  irregular 
brown  patches,  of  varying  sizes.  The  leaves  become  distorted 
and  unsightly,  and  redden  up  early  in  the  fall. 

Treatment.  Spray  the  trees  in  spring  before  the  buds  swell 
with  the  Hubbard-Riley  kerosene  emulsion,  diluting  with 
five  to  seven  parts 
of  water.  One 
thorough  applica- 
tion will  practi- 
cally exterminate 
the  insect. 

Psylla  (Psylla 
pyricola,  Forst.). 
—  Description.1 
The  eggs  of  this  FIG.  72.  -  Mite  causing  pear  leaf  blister,  greatly  enlarged. 

insect     are     laid 

early  in  spring,  during  warm  days  of  April,  by  adults  which 
hibernated  during  the  winter.  The  eggs  are  laid  in  small 
crevices  of  the  twigs ;  they  hatch  in  about  two  weeks,  and  pro- 
duce small  flattened  nymphs  (Fig.  73),  which  suck  the  juices  of 

the  tree.  They  occasionally 
appear  before  the  buds  have 
opened,  in  which  case  they 
hide  under  the  bud-scales  or 
under  the  bark,  and  wait  for 
the  coming  of  the  leaves. 
They  then  seek  the  axils  of 
the  leaves  and  move  but  little. 
They  secrete  large  quantities 
of  honey-dew,  often  being  en- 
tirely covered  with  it.  It  runs 
down  the  stems  of  the  tree, 
and  is  a  favorable  medium  for 
the  growth  of  a  dark  fungus 
which  causes  the  tree  to  ap- 
pear as  if  covered  with  soot. 
The  absence  of  this  color  is  a  good  indication  that  the  psylla  is 
not  present.  The  adult  insect  (Fig.  74)  appears  about  a  month 
after  the  egg  hatches.  It  closely  resembles  a  cicada  or  harvest- 

i  See  Slingerland,  Cornett  Agric.  Exp.  Sta.  1892,  Oct.  Bull.  44. 
z 


PIG.  73.  —  Immature  form  of  psylla. 


338 


The  Spraying  of  Plants. 


fly,  but  is  only  about  a  sixteenth  of  an  inch  in  length.  This 
winged  form  is  extremely  active  and  difficult  to  capture. 
Affected  trees  become  much  weakened ;  the  foliage  is  light 
green  or  yellowish,  and  if  the  tree  is  badly 
infested  both  the  fruit  and  the  foliage  drop 
prematurely  to  the  ground. 

Treatment.  The  best  method  of  over- 
coming this  destructive  insect  is  to  spray 
the  trees  with  kerosene  emulsion,  contain- 
ing from  4  to  5  per  cent  of  kerosene,  as 
soon  as  the  first  leaves  have  unfolded  in 
spring.  The  application  should  be  made 
very  thoroughly,  and  it  should  be  repeated 
once  or  twice  at  intervals  of  ten  days  or 
two  weeks,  if  there  is  reason  to  fear  that 
many  insects  have  survived.  Treatments 
made  during  the  summer  are  also  of  value, 
but  the  spray  must  be  copious,  and  it  must  be  thrown  with  great 
force  to  destroy  the  adults.  All  applications  should  also  be 
made  soon  after  a  rain,  for  then  the  honey-dew  is  mostly  washed 
away,  and  the  immature  insects,  or  nymphs,  may  be  reached 


FIG.  74.— Adult  psylla. 


FIG.  75.  —  Cherry  slug  upon  pear  leaf. 

more  easily  by  the  emulsion.     Winter  applications  of  kerosene 
emulsion  as  applied  for  plum  scales  have  been  recommended. 

Slug.  —  The  shiny  dark-colored  slug,  which  is  so  frequently 
seen  upon  pear  foliage  (Fig.  75),  is  identical  with  the  one  found 
upon  cherry  foliage.  A  description  of  the  insect  will  be  found 
under  CHERRY,  but  it  will  be  well  here  to  emphasize  the  neces- 


Pear,  Plum. 


339 


sity  of  treating  the  pest  before  much  damage  is  done.     Appli- 
cation should  be  made  seasonably  and  thoroughly. 


See  SYCAMORE. 
FUNGOUS  DISEASES. 


PLAXE-TREE. 
PLUM. 


Brown  Rot.     See  under  PEACH. 

Leaf  Blight;  Shot-hole  Fungus  (Cylindrosporium  Padi;   Sep- 
toria  cerasina,  Peck).  —  Description.     The  foliage  of  plums  and 


FIG.  76.  —  Shot-hole  fungns  of  plum. 


cherries  is  often  disfigured  in  early  summer  by  small  circular 
spots  about  an  eighth  of  an  inch  in  diameter.  The  spots  are  at 
first  of  a  purple  color,  but  later,  as  the  tissue  dries,  the  color 
changes  to  brown,  and  the  affected  areas  become  loosened  and 
drop  out.  This  causes  the  leaves  to  appear  as  if  pierced  by 
shot,  as  they  are  frequently  full  of  these  small,  round  holes 
(Fig.  76).  In  such  cases  the  foliage  turns  yellow,  drops  during 
the  summer,  and  the  trees  are  unable  to  mature  their  fruit. 
If  unchecked,  the  fungus  may  cause  serious  losses,  but  fortu- 
nately the  disease  is  easily  controlled. 


340 


The  Spraying  of  Plants. 


.  Treatment.  The  trees  should  be  sprayed  with  the  Bordeaux 
mixture  as  soon  as  the  leaves  appear,  the  application  being  re- 
peated at  intervals  of  two  or  three  weeks  until  about  the  middle 
of  July.  Clear  fungicides  should  be  applied  to  cherries  early 
in  the  season  to  avoid  staining  the  fruit,  and  the  same  precau- 
tion should  be  ob- 
served with  plums, 
although  the  Bor- 
deaux mixture  may 
be  continued  longer 
with  this  crop.  Four 
applications  should 
be  sufficient  even  in 
very  bad  seasons ; 
and  two  or  three 
will  generally  be 
found  sufficient. 

Leaf  Rust  (Puc- 
cinia  Pruni-spinosce, 
Pers. ).  —  Descrip- 
tion. In  general 
appearance  this  dis- 
ease is  very  similar 
to  the  preceding. 
The  affected  areas 
are  dull  red  upon 
the  upper  surface  of 
the  leaf  and  yellow- 
ish-brown on  the 
lower  surface,  but 
the  spots  are  small, 
and  frequently 
cause  the  foliage  to 
drop  prematurely. 
Give  the  same  treatment  as  for  the  plum  leaf 


\ 


FIG.  77.  —  Black  knot  of  pluin. 


Treatment. 
blight. 

Plum  Knot ;  Black  Knot ;  Plum  Wart  (Plowrightia  [Splicerta] 
morbosa,  Sacc.).  —  Description.  It  is  a  common  opinion  that  the 
black  knots  (Fig.  77)  found  so  generally  upon  plum  and  sour 
cherry  trees  are  caused  by  insects,  but  such  is  not  the  case. 


Plum.  341 

These  swellings  are  caused  by  a  fungus,  and  the  insects  find 
them  to  be  good  breeding-places,  which  explains  their  presence 
in  many  old  knots.  Although  the  fungus  has  long  been  known 
to  mycologists,  its  life  history  has  not  yet  been  entirely  de- 
termined; enough  is  kn'own,  however,  to  serve  as  a  safe  guide 
in  the  treatment  of  the  disease.  Early  in  spring,  when  growth 
starts,  these  swellings  begin  to  appear.  At  first  they  are  yellow- 
ish in  color,  but  later  this  changes  to  a  darker  shade.  During 
Mav  and  June  a  crop  of  spores  is  produced  upon  the  surface  of 
the  knots,  causing  them  to  appear  as  if  coated  with  a  thin  layer 
of  velvet.  This  soon  disappears,  and  then  the  knot  becomes 
darker  until  winter,  when  it  is  jet  black.  In  November  and  De- 
cember the  surface  of  the  knot  may  be  seen  to  be  thickly  cov- 
ered with  minute  black  elevations,  in  which  the  winter  spores 
are  borne.  These  are  distributed  during  the  latter  part  of 
winter.  The  spores  generally  gain  entrance  into  the  trees  at 
the  crotches  of  small  limbs  and  at  the  junction  of  annual 
growths.  They  cause  swellings  which  extend  along  the  younger 
branches  to  a  distance  of  four  or  five  inches  the  first  year.  All 
the  mycelium  does  not  die  during  the  winter,  so  the  following 
spring  the  formation  of  new  swellings  may  be  seen  at  the  edges 
of  the  old  knot.  In  this  manner  the  disease  may  live  from 
year  to  year,  or  until  the  limb  dies. 

Treatment.  The  general  recommendation  has  been  to  cut  out 
the  knots  and  destroy  them  as  soon  as  they  are  discovered.  It 
should  be  done  before  a  crop  of  spores  is  matured.  If  in  addi- 
tion to  this  the  trees  are  thoroughly  sprayed  with  the  Bordeaux 
mixture  during  the  warm  days  of  early  spring  before  growth 
starts,  and  again  when  the  buds  are  about  to  burst,  it  is  proba- 
ble that  the  winter  spores  may  be  rendered  harmless.  If  the 
crop  of  spores  produced  during  May  and  June  is  similarly  dis- 
posed of,  no  infection  need  be  feared.  Consequently  the  trees 
should  be  sprayed  for  the  third  time  with  the  Bordeaux  mix- 
ture during  the  latter  part  of  May,  and  again  about  the  middle 
of  June.  "These  applications  must  be  thoroughly  made,  and  if 
this  is  done  the  black  knot  fungus  may  be  practically  con- 
trolled. In  case  a  knot  appears  upon  a  large  limb,  or  upon  the 
trunk  of  a  tree  where  it  cannot  be  easily  removed,  it  should  be 
painted  with  pure  kerosene  oil.  This  will  destroy  the  knot  and 
also  the  living  tissue  surrounding  it ;  care  should  therefore  be 


342 


The  Spraying  of  Plants. 


exercised  in  the  application  of  the  oil  that  it  is  not  too  freely 
distributed.  By  mixing  some  coloring  matter  with  the  kero- 
sene the  treated  parts  may  easily  be  distinguished. 

Plum  Pockets;   Plum  Bladders  (Exocutcu*  [Taphrina]  Pruni, 
Fuckl.).  —  Description.     Plums  are  frequently  attacked  by  this 


FIG.  78.  —  Plum  pockets. 

fungus  soon  after  they  blossom.  The  affected  fruit  begins  to 
swell  (Fig.  78)  until  it  is  from  one  to  two  inches  in  length.  At 
first  the  plums  are  very  smooth,  but  they  are  yellow  in  color. 
Later  this  changes  to  gray,  the  appearance  being  caused  by  a 
thick  coating  of  the  spores  of  the  parasite.  This  color  is  then 
replaced  by  dark  brown  or  black,  and  towards  the  end  of  June 


Plum.  343 

the  fruit  falls  to  the  ground.  It  is  then  nearly  hollow,  and  rattles 
like  inflated  bladders.  The  walls  of  the  plum  are  fairly  thick, 
but  no  stone  or  pit  exists.  Wild  cherries  and  plums  are  also 
attacked  by  other  closely  related  fungi.  The  mycelium  of  these 
fungi  is  perennial,  so  that  the  disease  generally  appears  year 
after  year  on  the  same  tree.  It  attacks  the  leaves  and  stems  as 
well  as  the  fruit,  and  causes  the  affected  parts  to  become  swollen 
and  distorted. 

Treatment.  No  careful  work  appears  to  have  been  done  in 
controlling  the  fungi  that  cause  plum  pockets.  From  the  fact 
that  the  mycelium  has  been  found  growing  upon  the  twigs  and 
extending  to  the  young  leaves  and  fruits,  it  seems  probable  that 
the  copper  compounds  would  prove  valuable  in  controlling  the 
disease.  The  trees  should  be  sprayed  when  the  buds  begin  to 
swell,  and  again  just  before  the  blossoms  open.  The  disease 
may  also  spread  by  means  of  spores,  and  this  would  probably 
necessitate  applications  at  the  time  when  the  affected  fruit  is  of 
a  gray  color. 

Powdery  Mildew.     See  under  APPLE. 

Rot.     See  under  PEACH. 

INSECT  ENEMIES. 

Borers.     See  under  APPLE. 

Bud-moth.     See  under  APPLE. 

Canker-worm.     See  under  APPLE. 

Curculio  (Conotrachelus  nenuphar,  Herbst). —  Description.  The 
plum  curculio,  or  "  little  Turk,"  as  the  beetle  is  occasionally  called, 
is  the  worst  enemy  of  plum  growers.  The  adult  insect  is  scarcely 
a  fourth  of  an  inch  in  length.  It  is  grayish-brown  in  color,  and 
has  a  black  hump  on  the  center  of  each  wing  cover.  The  long 
snout  is  generally  curved  underneath  the  body.  The  eggs  are 
laid  in  the  young  plums  as  soon  as  the  blossoms  fall,  and  beetles 
may  still  be  present  even  six  weeks  later.  By  means  of  the 
snout  a  hole  is  bored  in  the  plum  and  the  egg  is  laid  within  it ; 
a  crescent-shaped  cut  is  then  made  about  the  part  containing 
the  egg  in  such  a  manner  that  a  small  lip  of  the  green  flesh  is 
formed.  Within  this  lip  the  egg-  is  secure.  It  hatches  in  a  few 
days,  the  grub  immediately  beginning  to  eat  its  way  towards  the 
center  of  the  fruit.  It  feeds  for  about  four  weeks,  being  then 
over  three-eighths  of  an  inch  in  length.  It  is  of  a  yellowish- 


344  The  Spraying  of  Plants. 

white  color,  the  head  being  pale  brown.  When  full  grown,  the 
larva  leaves  the  plum  and  descends  several  inches  into  the 
ground.  It  there  pupates,  and  the  mature  insect  appears  in 
the  fall,  or  sometimes  not  until  the  following  spring.  There  is 
but  one  brood  each  year. 

Treatment.  Spraying  the  trees  with  arsenites  has  been  recom- 
mended as  an  effective  method  of  destroying  the  curculio,  but 
many  growers  doubt  the  efficiency  of  the  practice  (see  pp.  68, 73). 
The  beetles  feed  some  time  before  laying  their  eggs,  and  such 
applications  are  designed  to  kill  the  adults  before  the  eggs  are 
laid.  The  first  treatment  should  be  made  as  soon  as  the  first 
leaves  unfold,  and  before  the  blossoms  open ;  the  second,  when 
the  blossoms  have  fallen ;  the  third,  about  two  weeks  later. 
Paris  green  and  lime  should  be  used,  each  at  the  rate  of  one 
pound  to  about  two  hundred  gallons  of  water. 

Another  method  of  destroying  the  curculio,  and  a  more  certain 
one,  is  to  jar  the  trees  early  in  the  morning  before  the  beetles 
are  active.  The  insects  fall  readily  from  the  trees,  and  may  be 
caught  on  sheets,  or  in  some  of  the  machines  now  used  for  the 
purpose.  When  the  insects  are  ordinarily  abundant,  the  trees 
should  be  jarred  every  other  morning,  beginning  the  work  as 
soon  as  the  blossoms  have  fallen.  In  severe  cases  the  trees 
must  be  treated  daily,  and  some  growers  have  repeated  the 
operation  again  in  the  evening,  as  the  insects  were  so  numer- 
ous. Jarring  the  trees  should  be  continued  until  the  beetles 
are  no  longer  caught  upon  the  sheets;  in  this  manner  the  fruit 
will  be  well  protected. 

Plum  gouger  (  Coccotorm  scutellaris,  Lee. ).  —  Description.  This 
insect  is  found  mostly  west  of  the  Mississippi  River.  It  is  a 
snout-beetle,  and  resembles  the  plum  curculio  in  many  respects. 
It  is,  however,  yellowish-brown  in  color,  and  when  the  egg  is 
laid  no  crescent  mark  is  made  about  the  point  of  insertion. 
The  larva  burrows  into  the  pit;  here  it  pupates,  and  late  in 
summer  or  early  fall  the  adult  appears.  The  winter  is  passed 
in  this  stage,  the  eggs  being  laid  the  following  spring  at  the 
same  time  as  are  those  of  the  plum  curculio. 

Treatment.  The  plum  gouger  is  controlled  in  the  same  man- 
ner as  the  plum  curculio. 

Plum-scale  (Lecanium  sp.).  —  Description.  This  scale  insect 
passes  the  winter  in  an  immature  form.  The  scales  are  about 


Plum,  Potato.  345 

one-twenty-fifth  of  an  inch  in  length;  they  are  very  narrow, 
flat,  and  of  a  brown  color.  About  the  first  of  April  these 
minute  scales  move  about  and  soon  fasten  themselves,  gener- 
ally to  the  under  side  of  the  small  branches.  They  increase 
rapidly  in  size,  so  that  in  two  months  they  are  from  two  to 
three-sixteenths  of  an  inch  in  length,  and  nearly  circular  in 
outline.  At  this  time  eggs  are  abundantly  produced  under 
the  large  brown  scales,  and  by  the  first  of  July  the  young  in- 
sects may  be  seen  crawling  over  the  branches.  They  pass  on 
to  the  under  side  of  the  leaves,  where  they  establish  themselves 
near  the  larger  veins.  Here  they  remain  until  the  latter  part 
of  August,  when  they  return  to  the  branches.  The  affected 
leaves  make  little  growth  and  look  unhealthy;  and  although 
the  scales  have  increased  but  little  in  size,  so  much  sap  has 
been  removed  that  the  trees  make  but  little  growth  and  the 
fruit  is  dwarfed.  When  the  insects  return  to  the  branches 
in  the  fall  they  are  of  a  rich  brown  color,  and  but  one-twenty- 
fifth  of  an  inch  in  length ;  in  this  form  they  hibernate,  and  the 
following  spring  they  again  become  active. 

Treatment.  In  the  fall,  as  soon  as  the  foliage  has  fallen,  spray 
the  trees  with  the  Hubbard-Riley  kerosene  emulsion  diluted 
with  four  parts  of  water.  A  weaker  emulsion  will  not  be 
effective,  and  a  stronger  one  may  injure  the  trees.  If  this 
work  is  thoroughly  done,  the  pest  can  be  practically  extermi- 
nated. The  application  may  be  made  any  time  from  Novem- 
ber to  April.  During  the  summer  months  the  foliage  interferes 
with  the  proper  application  of  the  spray,  and  the  emulsion  can- 
not be  applied  to  the  leaves  with  safety. 

Slug.     See  under  CHERRY. 

POPLAR. 
See  COTTOXWOOD. 

POTATO. 

FUNGOUS  DISEASES. 

Early  Blight  (Macrosporium  Solani,  E.  &  M.). —  Description. 
The  early  blight  of  potatoes  is  not  yet  fully  understood,  but 
much  of  the  early  dying  of  the  leaves  is  no  doubt  caused  by  the 
fungus  mentioned.  Observations  tend  to  show  that  the  injuries 
caused  by  the  flea-beetle  frequently  serve  as  starting-points  for  the 
disease  (Fig.  79).  Around  the  little  holes  made  by  these  insects, 


FIG.  79.— Early  blight  (Macrosporium  Solani)  on  potato  foliage. 
346 


Potato.  347 

there  may  be  seen  the  characteristic  browning  and  drying  of  the 
leaf-tissue,  rings  of  a  darker  color  being  visible  in  the  affected 
areas.  The  edges  of  the  leaves  are  more  generally  affected,  and 
as  the  small,  circular  spots  increase  in  size  they  run  together 
and  destroy  the  entire  outer  portions  of  the  leaf.  These  then 
turn  yellow  and  later  brown,  the  edges  curl  up,  and  tin  ally  all 
the  leaflets  and  the  petiole  are  destroyed.  The  injury  also 
extends  to  the  stems,  and  eventually  the  plant  dies.  The  pota- 
toes do  not  rot,  but  they  remain  small.  The  browning  of  the 
tissue  often  begins  during  July,  the  trouble  being  much  more 
severe  upon  mature  plants,  and  if  the  weather  is  moist  the 
trouble  appears  to  increase  less  rapidly  than  during  a  drought. 
Whether  the  early  blight  fungus  is  capable  of  entering  unin- 
jured tissue,  or  whether  its  entrance  is  entirely  dependent  upon 
the  work  of  the  flea-beetle,  has  not  yet  been  definitely  deter- 
mined, but  it  is  undoubtedly  true  that  the  abundance  of  this 
insect  has  considerable  influence  upon  the  prevalence  of  the 
disease.  In  some  cases  the  tissue  dies  apparently  without  the 
assistance  of  insects. 

Treatment.  Spraying  the  vines  with  the  Bordeaux  mixture 
has  given  fairly  good  results.  The  fungicide  should  be  used  at 
least  of  normal  strength,  and  it  appears  probable  that  a 
stronger  mixture  is  still  more  beneficial.  For  very  early  pota- 
toes the  first  application  should  be  made,  in  Xew  York,  iri  June ; 
for  medium  varieties  from  the  first  to  the  middle  of  July ;  while 
late  varieties  may  not  require  treatment  before  the  first  of 
August,  although  this  period  is  rather  late,  the  third  week  in 
July  being  perhaps  an  average  date.  Applications  should  be 
repeated  at  intervals  of  two  to  four  weeks,  three  treatments 
being  sufficient  in  seasons  favorable  to  the  fungus.  If  power 
sprayers  are  used,  each  row  should  receive  as  much  liquid  as 
is  thrown  by  two  Vermorel  nozzles  while  the  horse  is  walking 
across  the  field.  The  vines  should  be  very  thoroughly  treated. 

Rot ;  Blight ;  Late  Blight ;  Downy  Mildew  (Phytopldlwra  in- 
festans,  De  Bary).  —  Description.  Potato  blight,  or  rot,  has 
long  been  known  as  the  most  serious  and  destructive  of  all 
potato  troubles.  When  the  weather  is  warm  and  moist  the 
disease  spreads  with  great  rapidity,  so  that  an  entire  field  may 
be  destroyed  in  the  course  of  a  few  days.  The  first  symptom 
of  the  malady  is  the  browning  of  distinct  areas  upon  the  potato 


348 


The  Spraying  of  Plants. 


leaves  (Fig.  80);  the  affected  portions  may  be  small,  or  they 
may  extend  over  the  entire  leaflet.     In  this  respect  it  differs 


T* 


FIG.  80.— 


Potato  foliage  attacked  by  Phytophthora  infestans,  a  fungus  which 
causes  rotting  of  the  tubers. 


plainly  from  the  early  blight,  which  progresses  slowly,  and 
causes  distinct,  circular  spots,  while  those  produced  by  the 
rot  are  at  first  small  and  irregular  but  they  rapidly  extend 


Potato.  349 

under  favorable  circumstances  over  large  portions  of  the  foli- 
age. There  is  also  soon  formed  on  the  under  side  of  the  dis- 
colored parts  a  frost-like  coating,  which  is  composed  of  the 
summer  spores'and  of  the  threads  bearing  them.  Such  a  con- 
dition is  not  present  when  the  plants  are  attacked  by  the  early 
blight.  The  tubers  of  plants  attacked  by  the  phytophthora 
almost  invariably  rot,  and  it  is  on  this  account  that  the  losses 
occasioned  by  the  disease  are  often  so  great.  It  is  supposed 
that  the  tubers  are  infested  by  spores  whicli  fall  to  the  ground 
from  the  diseased  leaves  above,  and  not  by  the  mycelium  of  the 
fungus  growing  downward  within  the  stem  to  the  potatoes. 
The  spores  are  carried  through  the  soil  by  descending  water, 
and  upon  reaching  the  potatoes  they  gain  an  entrance  into  the 
tubers  and  cause  the  dry  rot  which  is  so  destructive.  It  is  pos- 
sible, however,  that  the  tubers  may  be  reached  by  both  methods. 

As  its  name  implies,  the  late  blight  does  not  appear  early  in 
the  season.  It  rarely  attacks  plants  before  the  middle  of  July, 
and  frequently  not  before  the  first  of  September.  Consequently 
there  is  abundant  time  for  treating  the  vines,  and  the  losses 
from  this  disease  need  not  be  heavy. 

Treatment.  The  potato  rot  caused  by  this  fungus  can  be 
almost  entirely  prevented  by  the  application  of  proper  fungi- 
cides. The  work  of  Professor  Jones  of  Vermont  has  clearly 
shown  that  the  disease  can  be  controlled,  and  experiments  made 
in  Europe  have  emphasized  the  same  fact.  Bordeaux  mixture 
is  the  best  fungicide  to  use,  as  there  is  no  danger  of  disfiguring 
the  crop,  nor  of  injuring  the  foliage.  It  should  be  made  at  least 
of  "normal"  strength,  and  when  made  according  to  the  "stand- 
ard "  formula,  it  has  been  still  more  effective.  But  the  latter 
mixture  is  applied  with  considerable  difficulty,  so  that  thorough 
applications  of  the  former  are  to  be  advised.  Treatments  may 
be  begun  any  time  during  July,  depending  upon  the  time  of 
planting  and  the  lateness  of  the  variety.  July  15th  is  generally 
early  enough  for  the  first  application  in  Xew  York.  It  should 
be  followed  by  one  or  twTo  others  made  at  intervals  of  one  to 
three  weeks,  depending  upon  the  weather.  If  the  potato  foliage 
is  thoroughly  covered  with  the  mixture,  little  trouble  need  be 
anticipated  from  this  disease. 

Bacterial  Blight.  —  Potatoes  also  appear  to  suffer  from  a  bac- 
terial disease  which  causes  the  death  of  the  parts  above  ground 


350  The  Spraying  of  Plants. 

and  also  a  rotting  of  the  tubers.  No  distinct  discoloration s  appear 
upon  the  leaves,  as  is  the  case  with  fungous  diseases,  but  the 
entire  plant  is  unhealthy  and  dies  prematurely.  Tubers  fre- 
quently show  discolored  patches  on  their  surface  before  decay- 
ing; a  soft  rot  results.  No  remedy  is  known,  except  rotation. 

Scab  (Oospora  scabies,  Thax.).  —  Description.  Potatoes  very 
commonly  suffer  from  the  attacks  of  a  fungus  which  causes  the 
skin  of  the  tubers  to  become  rough  or  scurfy  (Fig.  81),  the 
injury  often  penetrating  to  a  considerable  depth.  The  life 
history  of  the  fungus  is  not  yet  well  understood,  but  it  is 


FIG.  81.  —  Potato  scab. 

known  that  the  disease  may  be  communicated  to  new  tubers  by 
unclean  seed,  and  that  barnyard  manure,  lime,  or  ashes  may 
have  a  tendency  to  increase  the  disease.  Soil  in  which  scabby 
potatoes  have  been  produced  also  appears  capable  of  infecting 
later  crops.  One  kind  of  scab  is  caused  by  an  insect. 

Treatment.  Land  in  which  the  scab  fungus  is  found  should 
not  be  planted  to  potatoes,  and  only  clean  fertilizers  or  unin- 
fected  manure  should  be  applied.  Scabby  seed  may  be  cleaned 
by  soaking  it  for  an  hour  and  a  half  in  a  solution  of  corrosive 
sublimate,  using  one  ounce  of  the  poison  in  eight  or  nine  gal- 
lons of  water.  This  may  be  done  either  before  or  after  the 
potatoes  are  cut,  but  the  tubers  must  not  again  be  brought  in 


Potato.  351 

contact  with  the  disease.  It  is  safer  to  treat  the  seed  before  it 
is  cut;  and  if  care  is  taken  not  to  transfer  the  organism  to  the 
cleaned  potatoes,  no  scab  should  develop  upon  clean  land.  Hal- 
sted  has  been  successful  in  preventing  the  development  of  the 
disease  by  rolling  the  seed  in  sulphur.  He  used  the  sulphur  at 
the  rate  of  three  hundred  pounds  to  the  acre,  that  which  did 
not  adhere  to  the  potatoes  being  sprinkled  in  the  open  row. 

IXSECT  ENEMIES. 

Colorado  Potato-beetle ;  Potato-bug  ( Doryphora  10-lineata,  Say). 

—  Description.     This  insect  is  too  well  known  to  require  a  de- 
tailed description.     It  hibernates  during  the  winter  as  a  mature 
insect,  and  in  the  spring  it  begins  to  feed  upon  the  foliage  of 
eggplants  or  potatoes  as  soon  as  these  are  at  hand.     The  eggs 
are  laid  on  the  under  side  of  the  leaves.     They  are  bright  yel- 
low in  color,  and  easily  seen.     The   larvae   appear  in  about  a 
week,  and  the  plant  is  soon  stripped  of  its  foliage.     In  a  short 
time  the  grubs  become  full  grown ;  they  then  leave  the  plant 
and  pupate  in  the  surface  soil.     Here  they  remain  about  ten 
days,  when  the  mature  insect  again  appears.     There  are  three 
or  four  broods  each  year. 

Treatment.  Potato-beetles  are  easily  destroyed  by  spraying 
the  young  plants  with  an  arsenical  poison.  This  should  be 
done  early  in  the  season  so  that  the  first  beetles,  or  at  least 
the  first  brood  of  larvae,  may  be  exterminated.  The  poison 
should  be  made  about  one-fourth  or  one-third  stronger  than 
for  fruits,  as  these  insects  seem  to  require  more  poison  than 
most  others.  There  is  no  danger  of  injuring  potato  foliage  in 
this  manner. 

Flea-beetle  (Phyllolreta  vittata,  Fabr.;  Haltica  striolata,  Harris). 

—  Description.      This  species  of  flea-beetle,  as  well  as  several 
others,  makes  the  growing  of  many  garden  plants  a  difficult 
matter.     The  mature  beetles  are,  as  a  rule,  not  more  than  one- 
tenth  of  an  inch  in  length.     They  are  very  active,  and  move  so 
quickly  that  their  popular  name   is  very  appropriate.     The 
beetles  appear  early  in  spring  and  eat  out  little  cavities  in  the 
tender  foliage  of  young  plants,  often  to  such  an  extent  that  the 
plants  are  ruined.     If  the  work  of  the  beetles  does  not  destroy 
the  crop,  the  injured  parts  afford  conditions  suitable  to  the 
growth  of  certain  fungi,  and  these  two  parasites  may  succeed 


352  The  Spraying  of  Plants. 

in  accomplishing  that  which  each  alone  could  not  have  done. 
There  appear  to  be  several  broods  of  the  beetles  each  season. 

Treatment.  No  uniformly  effective  remedies  are  known. 
Good  results  have  been  obtained  by  dusting  the  young  plants, 
while  wet,  very  freely  with  tobacco  dust.  Arsenites  have  also 
been  recommended,  as  well  as  lime,  ashes,  plaster,  and  kerosene 
emulsion.  Bordeaux  mixture  and  soap  has  given  good  results 
in  certain  cases  when  thoroughly  applied. 


FUNGOUS  DISEASES. 

The  privet  is  comparatively  free  from  fungous  diseases,  one 
form  of  blight  which  occasionally  appears  rather  suddenly  being 
the  most  serious.  It  is  probably  due  to  Phyllosticta  Ligustri,  Sacc. 
Little  attention  has  been  given  it,  but  the  use  of  Bordeaux  mix- 
ture is  the  most  promising  line  of  treatment. 

INSECT  ENEMIES. 

Privet  Web-worm  (Margarodes  quadristigmalis,  Gn.).  —  De- 
scription. The  adult  moth  is  almost  entirely  white,  a  narrow 
brown  line  marking  the  anterior  edge  of  the  front  wings  ;  there 
are  also  a  few  brown  dots  and  markings  at  the  outer  edges  of 
both  pairs  of  wings.  The  body  is  almost  entirely  white.  It  is 
nearly  five-eighths  of  an  inch  in  length,  the  wings  expanding 
about  one  and  one-fourth  inches.  Eggs  are  laid  in  spring,  near 
the  mid-vein  of  the  leaves  ;  they  hatch  in  less  than  a  week,  and 
the  larvae  immediately  begin  to  feed  upon  the  foliage.  They 
vary  in  color  from  yellowish-green  to  a  very  dark  green,  while 
along  the  back  are  situated  two  rows  of  small  black  warts.  The 
head  is  yellowish-green.  The  caterpillars  feed  for  about  three 
weeks  ;  they  then  pupate,  the  moth  appearing  about  eight  days 
later.  There  are  at  least  four  broods  of  this  insect  each  year  in 
the  latitude  of  Washington. 

Treatment.  The  free  use  of  arsenites  or  of  kerosene  emulsion 
will  undoubtedly  exterminate  the  insect  if  the  work  is  begun 
when  the  first  larvae  are  seen  in  spring. 

FUNGOUS  DISEASES.     PUMPKIN. 
Powdery  Mildew.     See  under  MUSKMELON. 
INSECT  ENEMIES.     See  under  CUCUMBER. 


Quince. 


353 


FUNGOUS  DISEASES. 


QUINCE. 


Black  Rot  (Sphceropsis  Malorum,  Peck).  —  Description.  Apples 
and  pears,  as  well  as  quinces,  suffer  from  the  fungus  which 
causes  black  rot.  The  fruit  is  generally  not  attacked  until  it  is 
at  least  one-half  grown. 
Infection  takes  place,  as 
a  rule,  at  the  blossom 
end.  A  small  brown 
spot  appears  upon  the 
surface,  and  as  it  in- 
creases in  size  dark  pim- 
ples appear  upon  the 
part  first  affected.  Later 
the  fruit  cracks,  and 
spores  are  freely  dis- 
tributed. The  diseased 
quinces  frequently  re- 
main hanging  on  the 
trees  throughout  the 
winter,  and  serve  as  ex- 
cellent sources  of  infec- 
tion. 

Treatment.  As  the 
malady  appears  late  in 
the  season,  the  applica- 
tion of  the  Bordeaux 
mixture  can  scarcely  be 
recommended.  Clear 
fungicides  should  be  used,  and,  if  thoroughly  applied,  the  dis- 
ease, which,  as  a  rule,  is  not  serious,  can  probably  be  held  in 
check  by  two  or  three  treatments. 

Blight.     See  under  PEAR. 

Leaf  Blight;  Fruit  Spot;  Leaf  Spot  (Entomosporium  macula- 
turn,  Lev.).  —  Description.  Quince  foliage  is  generally  affected 
by  the  leaf-blight  fungus  during  early  summer.  Fig.  82 
represents  quince  foliage  dotted  with  the  small  circular  spots 
which  are  produced  by  the  fungus.  These  are  of  a  reddish- 
brown  color,  and  although  at  first  circular  in  form,  when  several 

2  A 


FIG.  82.  —  Quince  foliage  affected  with  leaf  blight. 


354 


The  Spraying  of  Plants. 


are  united,  the  diseased  part  assumes  an  irregular  outline.  Badly 
infested  leaves  turn  yellow  and  fall  to  the  ground  during  the 
latter  part  of  summer,  or  early  in  the  fall.  Trees  very  com- 
monly lose  all  their  leaves  in  this  manner.  Upon  the  fruit,  if 
the  attack  takes  place  after  the  quince  is  nearly  grown,  dark 
brown  or  nearly  black  sunken  areas  are  formed,  these  being 
more  or  less  thickly  scattered  over  the  surface,  as  shown  in 
Fig.  83.  If  the  quince  is  affected  while  it  is  small,  its  shape 

may  be  much  altered,  for 
the  flesh  becomes  cracked 
and  corky  in  the  diseased 
places.  Such  fruit  is  only 
too  familiar  to  quince 
growers.  The  fungus  also 
attacks  pears. 

Treatment.  The  method 
of  treating  this  disease  has 
already  been  mentioned 
under  leaf  blight  of  the 
pear.  The  two  fruits  are 
treated  in  a  similar  man- 
ner, but  the  applications 
made  upon  the  quince 
during  the  latter  part  of 
June  and  in  July  are  the 
most  important  ones. 

Ripe  Rot.  See  under 
APPLE. 

Rust  (Rcestelia  auranti- 
aca,  Pk.).  —  Description. 
This  disease  (Fig.  84)  "is 
very  conspicuous  upon  the  fruit,  as  it  covers  the  injured  portion 
of  the  quince  with  an  orange,  fringe-like  growth.  The  tube-like 
projections  of  the  fungus  contain  numerous  spores,  and  when 
this  stage  is  apparent,  the  fruit  is  already  irrevocably  ruined. 
Sometimes  the  entire  young  fruit  is  involved,  and  it  may  die 
and  fall;  but  more  often  the  fruit  hangs  upon  the  tree,  and 
the  diseased  portion  becomes  dry,  hard,  black,  and  sunken. 
.  .  .  This  rust  fungus  also  penetrates  the  twigs,  and  often 
causes  knots  to  appear,  resembling  the  black  knot  of  the 


FIG.  83.  —  Quince  attacked  during  the  latter 
part  of  the  season  by  fruit  spot. 


Quince,  Raspberry. 


355 


plum." l    The  life  history  of  this  fungus  is  similar  to  that  caus- 
ing the  rust  of  apples,  which  see. 
Treatment.     See  under  APPLE. 

INSECT  ENEMIES. 

Borers.     See  under  APPLE. 
Slug.     See  under  CHERRY. 


FIG.  84.  —  Young  quinces  attacked  by  rust. 


INSECT  ENEMIES. 


RADISH. 


Maggot.     See  under  CABBAGE. 


RASPBERRY. 

Anthracnose ;  Cane  Rust  (Glceospoj-ium  necator,  E.  &  E.). — 
Description.  This  fungus  attacks  the  young  canes  of  raspber- 
ries, blackberries,  and  dewberries.  It  appears  during  the  latter 
part  of  June  and  during  July,  attacking  the  lower  parts  of  the 

i  Bailey,  Cornell  Agric.  Exp.  Sta.  1894,  Dec.  Bull.  80,  625,  626. 


356 


The  Spraying  of  Plants. 


canes  first.  The  affected  parts  are  circular  but  later  oval  in 
outline  (Fig.  85),  the  central  part  is  gray  in  color,  and  this  is 
surrounded  by  a  distinct  purple  rim.  These  areas  are  sunken, 
and  when  several  run  together  they  may  cause  the  cracking  of 
the  cane,  or  even  its  death.  The  leaves  are  also  attacked  to  a 
limited  extent,  but  with  no  such  serious  results.  When  the 
fruit  stems  are  diseased,  the  berries  are  frequently  prevented 
from  ripening,  and  consequently  they  dry  up  on  the  bushes. 

Treatment.  An- 
thracnose  has  not 
yet  been  very  suc- 
cessfully treated. 
The  best  recom- 
mendations which 
can  now  be  given 
are  to  spray  the 
bushes  thoroughly 
with  the  copper  sul- 
phate solution  be- 
fore the  buds  swell 
in  the  spring,  and 
to  follow  this  by  re- 
peated and  copious 
applications  of  the 
Bordeaux  mixture 
at  intervals  of  two 
weeks  until  mid- 
summer. A  clear 
fungicide  may  be  necessary  to  avoid  staining  the  fruit.  Even 
this  treatment  may  not  hold  the  disease  in  check.  In  that  case 
perhaps  the  best  method  to  follow  is  to  cut  off  all  growth  close 
to  the  ground  during  the  fall  or  spring,  and  then  burn  the  canes. 
This  means  the  loss  of  one  year's  crop,  but  the  source  of  infec- 
tion would  no  doubt  be  so  reduced  that  but  little  disease  should 
appear  during  the  next  few  years,  especially  if  the  bushes  are 
also  sprayed  as  above  described.  Or  the  entire  plantation  may 
be  pulled  up  and  a  new  one,  composed  of  less  susceptible  vari- 
eties, may  be  set  upon  other  land. 

Orange-rust;   Red-rust  (Cceoma  luminatum,  Link).  —  Descrip- 
tion.    This  fungus  is  found  upon  blackberries  and  raspberries. 


FIG.  85.  —  Easpberry  anthracnose,  or  cane  rust. 


Raspberry.  357 

It  possesses  a  perennial  mycelium,  so  that  when  a  plant  is  once 
infested  it  cannot  be  cured.  The  fungus  has  two  forms  which 
were  formerly  supposed  to  be  distinct  plants.  One  form  is 
known  as  Puccinia  Peckiana ;  it  attacks  the  foliage,  and  pro- 
duces spores  which  germinate  in  the  fall  or  spring.  The  myce- 
lium enters  the  canes  of  the  host-plant,  probably  by  means  of 
the  underground  parts,  and  from  there  it  spreads  to  the  vari- 
ous branches.  The  copious  production  of  orange-colored  spores 
on  the  under  side  of  the  foliage  of  diseased  plants  is  the  result 
of  such  infection.  This  condition  is  preceded  by  an  appear- 
ance which  is  easily  recognized :  the  leaves  are  smaller,  and 
they  have  a  pale  green  color  which  distinguishes  them  from 
the  healthy  tissues. 

Treatment.  The  only  practical  remedy  yet  known  is  to  dig 
out  and  destroy  affected  plants  as  soon  as  they  are  discovered. 
Spraying  the  foliage  with  a  fungicide  to  prevent  the  entrance 
of  the  fungus  into  the  leaves  might  be  followed  by  good  results. 

INSECT  ENEMIES. 

Cane-borer  (Oberea  bimaculata,  Oliv.).  —  Description.  The 
mature  insect  is  a  slender,  black  beetle  about  half  an  inch  in 
length.  During  June  it  lays  its  eggs  in  the  young  shoots  which 
grow  from  the  base  of  the  plant.  A  row  of  punctures  is  made 
above  and  below  the  place  in  which  the  egg  is  inserted.  The 
egg  soon  hatches  and  the  grub  begins  to  burrow  downward. 
By  autumn  it  has  reached  the  roots  of  the  plant.  The  follow- 
ing spring  the  adults  again  appear. 

Treatment.  The  puncturing  of  the  young  canes  when  the 
eggs  are  laid  causes  the  tips  to  wilt  and  on  this  account  the 
affected  shoots  are  readily  seen.  They  should  be  cut  off  below 
the  injured  part,  and  destroyed.  The  canes  should  also  be 
watched  during  late  summer,  and  any  which  are  found  wilting 
should  be  cut  out  close  to  the  ground  and  burned. 

Sawfly  ;  Raspberry-slug  (Selandria  Rubi,  Harris).  —  Descrip- 
tion. During  May  and  early  in  June  the  raspberry  sawfly  may 
be  seen  among  the  canes  of  these  plants.  It  is  a  black,  four- 
winged  fly,  the  abdomen  being  tinged  with  red.  The  eggs  are 
laid  within  the  leaf,  generally  near  the  veins.  The  larvae  are  at 
first  nearly  white,  but  later  they  become  dark  green  and  are 
thickly  covered  with  soft  spines  of  the  same  color.  When 


358  The  Spraying  of  Plants. 

grown,  the  larvae  are  about  half  an  inch  in  length.  They  feed 
upon  the  foliage  of  the  plants,  and,  if  present  in  considerable 
numbers,  the  foliage  may  be  almost  entirely  devoured.  During 
June  the  insect  pupates,  but  the  adult  does  not  appear  until  the 
following  spring. 

Treatment.  The  slugs  are  readily  destroyed  by  the  arsenites, 
hellebore,  or  pyrethrurn.  But  some  applications  must  neces- 
sarily be  made  while  the  plants  are  in  blossom ;  this  exposes 
bees  to  the  action  of  the  poisons,  and  large  numbers  of  these 
insects  are  destroyed  whenever  enough  poison  to  kill  the  slugs 
is  applied.  Under  such  circumstances  it  is  a  question  of  killing 
the  bees  or  tearing  out  the  plants.  Hand  picking  might  be 
practiced,  and  if  carried  on  for  a  year  or  two  would  greatly 
reduce  the  numbers  .of,  the  pest.  Kerosene  emulsion  might  also 
be  tried,  the  blossoms  being  touched  as  little  as  possible. 

ROSE. 

Black  Spot;  Leaf  Blight  (Actinonema  Rosce,  Fries).  —  Descrip- 
tion. During  early  summer  the  foliage  of  roses  suffers  from  the 
attacks  of  a  fungus  which  causes  the  formation  of  irregular, 
black  spots  upon  the  upper  surface  of  the  leaves  (Fig.  86). 
The  spots  eventually  become  nearly  circular;  their  edges  are 
apparently  fringed  with  delicate  white,  and  later  in  the  season 
the  affected  leaves  turn  yellow,  and  fall  to  the  ground ;  at  this 
time  the  spots  may  be  fully  half  an  inch  in  diameter.  Roses 
grown  indoors  or  in  the  open  appear  to  be  equally  affected. 

Treatment.  Fungicides  containing  copper  will  check  the  dis- 
ease if  the  treatments  are  begun  as  soon  as  the  buds  open  in 
spring.  Clear  solutions  are  to  be  preferred.  Removing  and 
destroying  the  affected  leaves  will  also  tend  to  lessen  the 
trouble. 

Leaf  Spot  (Cercospora  roscecola,  Pass.).  —  Description.  The 
spots  formed  by  this  fungus  are  dark  red  or  nearly  black,  the 
edges  of  the  well-defined  areas  being  mostly  of  a  red  color. 
The  center  changes  to  a  grayish-brown  color  as  the  season 
advances.  Only  those  plants  which  grow  out  of  doors  are 
affected,  the  foliage  being  the  part  generally  attacked. 

Treatment.  The  treatment  described  under  Black  Spot, 
above,  is  also  recommended  for  this  disease. 


Rose. 


359 


Mildew  (Sphcerotheca  pannosa,  Lev.).  —  Description.  This 
fungus  attacks  roses  which  are  grown  under  glass  and  also 
those  out  of  doors.  It  checks  the  growth  of  the  young  shoots, 
and  causes  the  leaves  to  remain  dwarfed  and  curled,  the  edges 


FIG.  86.  —  Black  spot  of  roses. 


being  generally  rolled  downward.  At  the  same  time,  a  white 
powdery  growth  entirely  covers  the  affected  areas,  and  the 
plants  soon  become  so  weakened  that  they  possess  no  practical 
value.  Fig.  87  represents  a  leaf  partially  affected. 

Treatment.     The  treatment  of  mildews  affecting  plants  grown 
under  glass   has   already  been  discussed  under  GREENHOUSE 


360 


The  Spraying  of  Plants. 


PESTS.  Many  of  the  same  remedies  will  also  prove  of  value 
with  plants  grown  in  the  border,  sulphur  and  the  copper  com- 
pounds being  particularly  recommended. 


FIG.  87.  —  Rose  leaf  attacked  by  mildew. 


Phragmidium  (Pkragmidium  speciosum,  Fries).  —  De 
scription.  The  stems  of  roses  suffer  severely  from  this  fungus. 
The  mycelium  is  perennial,  and  the  affected  places  show  irregu- 
lar elevated  areas  on  the  stem  (Fig.  88).  They  are  black  in 
color,  and  consist  of  innumerable  spores  borne  upon  slender 
filaments.  In  severe  cases  the  diseased  stems  die. 


Rose.  361 

Treatment.  The  treatment  recommended  against  the  rust 
will  also  apply  to  this  disease.  In  addition,  however>  the 
affected  steins 'should  be  removed  as  soon  as  discovered. 

Rust  (Phragmidium  mucronatum,  Winter).  —  Description.  All 
the  young  green  parts  of  the  rose  are  subject  to  the  attacks  of 


I 


FIG.  88.  —  Rose  Phragmidium. 


the  rust  fungus.  It  causes  the  formation,  in  early  summer,  of 
small  reddish-yellow  spots  which  gradually  increase  in  size  as 
the  season  advances.  The  stems  frequently  become  bent  and 
twisted  by  the  growth  of  the  mycelium.  During  August,  the 
color  of  the  spots  changes  to  dark  red.  In  the  fall,  small  dar> 


362  The  Spraying  of  Plants. 

bodies  are  produced  on  the  under  side  of  the  leaves ;  they  con- 
tain the  spores  which  preserve  the  fungus  through  the  winter. 

Treatment.  The  plants,  and  the  soil  about  them,  should  be 
sprayed  in  early  spring  before  growth  has  commenced  with  the 
copper  sulphate  solution.  After  the  buds  have  burst  the  Bor- 
deaux mixture  should  be  used,  or  some  clear  fungicide  which 
will  not  stain  the  leaves.  These  applications  should  be  contin- 
ued until  midsummer  at  intervals  of  two  or  three  weeks.  Raking 
and  burning  the  leaves  in  the  fall  will  also  diminish  the  trouble. 

INSECT  ENEMIES. 

Mealy-bug.     See  under  GREENHOUSE  PESTS. 

Rose-chafer ;  Rose-beetle ;  Rose-bug  (Macrodactylus  subspinosus, 
Fabr.).  —  Description.  The  beetles  appear,  as  a  rule,  early  in 
June.  They  are  about  half  an  inch  in  length  and  of  a  yellowish- 
brown  color,  the  legs  being  pale  red.  The  beetles  feed  for  about 
a  month  after  the  time  of  their  first  appearance.  They  devour 
nearly  all  kinds  of  foliage,  and  in  some  localities  fruit  planta- 
tions are  annually  almost  ruined  by  these  insects.  Shortly  be- 
fore the  disappearance  of  the  adults,  the  eggs  are  laid  in  the 
ground  near  the  surface.  The  grubs  feed  upon  the  roots  of 
various  plants  and  in  the  fall  they  descend  below  the  frost  line 
and  there  pass  the  winter.  In  the  spring  they  ascend  to  the 
surface  and  pupate,  the  adult  emerging  as  above  stated.  There 
is  but  one  brood  each  year. 

Treatment.  No  satisfactory  remedies  for  the  destruction  of 
the  rose-beetle  are  known.  The  insect  can  persist  only  on 
sandy  land,  for  heavier  soil  prevents  the  grubs  from  descending 
to  a  proper  depth.  It  is,  therefore,  only  on  sandy  land  that  the 
pest  is  to  be  feared.  The  following  methods  of  exterminating 
the  insect  have  been  recommended,  but  none  are  entirely  satis- 
factory :  "  Hand  picking.  Knocking  off  on  sheets  early  in  the 
morning.  Bagging.  Pyrethrum.  Kerosene  emulsion.  Py- 
rethro-kerosene  emulsion.  Eau  celeste.  It  is  said  to  prefer 
Clinton  grapes,  spireas,  rose-bushes,  and  magnolias,  and  it  has 
been  suggested  that  these  plants  be  used  as  a  decoy.  Open 
vials  of  bisulphide  of  carbon  hung  in  bushes  and  vines  are 
recommended  by  some.  Sludge-oil  soap,  a  manufactured  ma- 
terial. Spraying  with  dilute  lime  whitewash.  Hot  water,  at 
a  temperature  of  125°  to  130°  F.  To  prevent  the  insects  from 


Rose,  Spinach.  363 

breeding,  keep  the  light  lands  —  in  which  they  breed — under 
thorough  cultivation,  and  especially  never  seed  them  down." l 

Rose  Leaf-hopper  (Typhlocyba  Rosce,  Harris).  —  Description. 
These  insects  are  generally  found  upon  the  under  side  of  the 
leaves,  but  when  disturbed  they  move  or  fly  rapidly  from  place 
to  place.  They  live  upon  the  juices  of  the  plants,  and  are  fre- 
quently serious.  The  mature  insect  is  less  than  a  fourth  of  an 
inch  in  length ;  its  wing  covers  are  nearly  transparent,  and  the 
body  is  yellowish- white.  There  are  several  broods.  The  af- 
fected leaves  show  irregular,  white  markings  on  their  upper 
surface,  and  in  this  manner  the  presence  of  the  pest  may  easily 
be  observed. 

Treatment.  The  same  remedies  mentioned  under  CURRANT 
GREEX-LEAF-HOPPER  may  also  be  employed  against  this  insect. 

SHADE   TREES;    SHRUBS. 

There  are  many  fungi  and  insects  attacking  other  plants 
than  those  mentioned  individually  in  this  work,  but  it  is 
scarcely  practicable  to  describe  each  in  detail.  The  reader  is 
referred  to  Chapter  VI.,  in  which  general  directions  will  be 
found ;  it  is  hoped  these  will  serve  as  guides  in  the  treatment 
of  any  trouble  which  it  is  desired  to  overcome. 

SPINACH. 

Anthracnose  (ColletotricJium  Spinacece,  E.  &  H.).  —  Description. 
The  affected  parts  are  generally  circular  in  form;  they  soon 
produce  brown  pustules,  and  the  color  of  the  spot  gradually 
changes  to  gray.  The  fungus  spreads  with  great  rapidity, 
attacking  the  old  and  the  young  leaves  indiscriminately. 

Mildew  (Peronospora  effiisa,  Rabenh.).  —  Description.  Spin- 
ach grown  under  glass  is  frequently  attacked  by  this  fungus. 
The  diseased  foliage  shows  "  gray,  slightly  violet  patches  of  a 
velvety  texture  upon  the  under  side  of  the  leaves,  while  from 
the  upper  side  they  have  a  pale  yellow  shade  due  to  the  loss  of 
the  green  color."2  Dr.  Halsted  has  also  described  three  other 
fungous  diseases  of  spinach,  viz.  black  mold,  leaf  blight,  and 

»  Bailey,  Horticulturist'1  s  Rule-Book,  1895,  42. 

*  Halsted,  N.  J.  Agric.  Exp.  Sta.  1890,  July,  Bull.  70,  5. 


364  The  Spraying  of  Plants. 

white  smut,  and  the  reader  is  referred  to  the  bulletin  mentioned 
below  for  detailed  descriptions. 

Treatment.  All  spinach  diseases  are  controlled  with  difficulty, 
since  the  parts  attacked  by  the  fungi  grow  quickly,  and  they 
are  then  used  as  food.  Fungicides  would  undoubtedly  prevent 
the  entrance  of  the  parasites,  but  the  market  value  of  the  crop 
would  be  lessened  to  such  an  extent  that  the  applications  can 
scarcely  be  advised.  The  plants  might  be  sprayed  with  dilute 
solutions  of  clear  fungicides,  but  comparatively  little  has  as  yet 
been  done  in  this  direction.  The  destruction  of  all  infested 
leaves  or  plants  appears  to  be  the  most  advisable  procedure. 

SQUASH. 
FUNGOUS  DISEASES. 

Powdery  Mildew.     See  under  MUSKMELON. 

INSECT  ENEMIES. 
See  under  CUCUMBER. 

STRAWBERRY. 

Leaf  Blight;  Rust;  Sunburn  (Sphcerella  Fragarice.,  Sacc.). — 
Description.  The  foliage  of  strawberries  is  subject  to  the 
attacks  of  a  fungus  which  may  appear  at  any  time  during  the 
growing  season.  The  first  symptom  of  the  disease  is  the  for- 
mation of  small  purple  spots  which  gradually  increase  in  size 
until  they  are  from  an  eighth  to  a  quarter  of  an  inch  in 
diameter  (Fig.  89).  The  purple  color  is  early  replaced  by  a 
clear,  reddish-brown,  which  becomes  of  a  still  lighter  shade  as 
the  season  advances ;  the  edges  of  the  spots,  however,  generally 
remain  purple.  Badly  infested  leaves  turn  dark  and  are  of  no 
value.  The  fungus  passes  the  winter  by  means  of  spores,  and 
by  mycelium  contained  within  the  leaves.  This  disease  is  fre- 
quently very  serious,  especially  upon  certain  varieties. 

Treatment.  Spraying  the  plants  with  the  Bordeaux  mixture 
will  check  the  trouble.  Applications  should  be  begun  as  soon 
as  growth  starts  in  spring,  and  non-bearing  plants  may  be 
treated  throughout  the  summer,  the  treatments  being  made 
at  intervals  of  three  or  four  weeks.  Bearing  plantations  will 
derive  benefit  from  a  treatment  made  when  growth  starts  in 


Strawberry. 


365 


the  spring,  and  from  another  made  when  the  first  blossoms 
open.  After  harvesting  the  fruit,  it  is  a  good  plan  to  mow  off 
the  old  foliage,  then  to  remove  and  destroy  it.  Burning  the 
strawberry  patch  over  is  frequently  followed  by  bad  results. 
The  new  growth  should  then  be  sprayed  at  intervals  of  three 
or  four  weeks  until  two  or  three  applications  have  been  made. 

Mildew  (Sphcerotheca   Castagnei,  Lev.).  —  Description.     This 
fungus  grows  on  the  berries,  and  also  on  the  surface  of  the 


FIG.  89.  —  Strawberry  leaf  blight. 


strawberry  leaves,  during  the  summer.  It  covers  them  with 
a  thin  net  of  mycelium  which  resembles  delicate  cobweb. 
Affected  leaves  curl  and  appear  as  if  suffering  from  want  of 
water  (Fig.  90).  The  disease  is  rarely  serious. 

Treatment.  When  the  malady  is  first  seen,  spray  the  plants 
with  a  fungicide  containing  copper.  Sulphur,  if  scattered  upon 
the  leaves  and  between  the  plants,  is  also  said  to  check  the 
disease,  since  the  heat  of  the  sun  at  this  season  of  the  year  is 
sufficiently  great  to  cause  fumes  to  be  given  off  freely. 


366  The  Spraying  of  Plants. 

INSECT  ENEMIES. 

Leaf-roller  (Phoxopteris  comptana,  Frol.).  —  Description.  The 
adult  insect  is  a  small,  brown  moth  measuring  about  half  an 
inch  across  the  wings.  It  appears  in  early  spring  and  lays  its 
eggs  upon  the  leaves  of  the  strawberry,  although  the  raspberry 
and  blackberry  are  rarely  affected.  The  larvae  are  greenish 
brown,  and  when  full  grown,  nearly  half  an  inch  in  length,  but 
rather  slender.  They  mature  in  June  after  having  spun  a  web 
which  causes  the  familiar  rolling  upward  of  the  leaflets.  The 
soft  tissue  of  the  leaf  is  eaten,  and  what  remains  turns  reddish 
brown,  giving  the  plant  a  burned  appearance.  There  are  two 
broods  in  the  North,  the  winter  being  passed  in  the  pupal  stage. 

Treatment.  Spray  the  plants  during  August,  when  the  second 
brood  of  larvae  appears,  with  an  insecticide  such  as  Paris  green 
or  London  purple.  Two  applications  may  be  required.  Or  the 
foliage  may  be  cut  and  burned,  'for  the  first  brood  pupates  in 
the  rolled  leaf,  and  in  this  manner  it  may  be  practically  exter- 
minated. 

Sawfly;  Slug  (Emphytus  maculatus,  Norton).  —  Description. 
"  The  four-winged  fly  appears  in  spring,  and  deposits  its  eggs 
within  the  tissues  of  the  leaf  or  stem.  The  larvae  hatch  in  a 
short  time  and  feed  upon  the  leaf,  gnawing  small,  circular 
holes  at  first  like  those  eaten  out  of  currant  and  gooseberry 
leaves  by  young  currant-worms.  They  develop  in  five  or  six 
weeks  into  pale  green  worms  about  three-fourths  of  an  inch 
long.  The  larvae  now  go  slightly  beneath  the  surface,  where 
they  form  cocoons  within  which  they  change  to  the  pupa  state, 
and  later  emerge  as  flies.  In  the  southern  states  there  are  two 
broods  each  season,  while  at  the  North  there  appears  to  be  but 
one."i 

Treatment.  Burn  the  foliage  as  soon  as  the  crop  is  harvested, 
or  spray  with  hellebore  or  Paris  green  before  there  is  danger  of 
poisoning  the  fruit.  Plants  which  are  not  bearing  may  be 
sprayed  with  an  arsenite  when  the  worms  first  appear,  and 
again  later  if  necessary. 

Tarnished  Plant-bug  (Lygus  pratensis,  Linn.).  —  Description. 
This  bug  is  about  one-fourth  of  an  inch  in  length.  It  is  very 
variable  in  color,  some  being  dark  yellow,  and  others  nearly 

»  Weed,  "  Insects  and  Insecticides,"  1891,  92. 


Strawberry 


367 


black.  The  adult  hibernates  during  the  winter,  but  in  the 
spring  it  sucks  the  juice  of  the  growing  plants,  preferring  to 
obtain  it  from  the  young  fruits,  which  are  in  consequence 
dwarfed.  Eggs  are  laid  early  in  spring,  and  soon  both  adult 


FIG.  90.  —  Strawberry  leaf  curled  by  the  mildew. 

and  immature  forms  may  be  found.  A  great  many  species  of 
plants  suffer  later  in  the  season,  and  as  there  are  from  two  to 
four  broods  each  year,  much  injury  may  be  done. 

Treatment.     Pyrethrum  powder  dusted  freely  upon  affected 
plants  will  destroy  the  insects ;  this  is  probably  the  best  rem« 


368  The  Spraying  of  Plants. 

edy.    Kerosene  emulsion  is  also  effective,  but  there  is  danger  oi 
tainting  the  fruit. 

SWEET  POTATO. 

FUNGOUS  DISEASES. 

Black  Rot  (Ceratocystis  Jimbriata,  E.  &  H.).  —  Description. 
The  fungus  causes  large,  greenish-black  patches  to  appear  upon 
the  tubers;  the  dark  color  eventually  extends  deeply  into  the 
potato,  entirely  ruining  it.  The  disease  may  attack  the  young 
plants  in  the  seed  beds,  the  infection  coming  either  from  the 
soil  or  from  unhealthy  tubers.  When  the  young  sprouts  are 
affected,  the  stems  near  the  ground  become  discolored  by  dark 
lines  or  blotches,  and  the  lower  leaves  frequently  suffer  in  the 
same  manner.  The  shoots  frequently  die  beyond  the  point  of 
attack. 

Treatment.  The  use  of  unaffected  potatoes  for  producing  the 
sets  is  essential.  No  diseased  sprouts  should  be  planted,  and,  if 
possible,  land  that  is  free  from  the  fungus  should  be  used  for 
the  crop.  Spraying  with  copper  compounds  may  materially 
assist  in  checking  the  trouble  in  the  field,  and  soaking  the 
tubers  a  short  time  in  the  ammoniacal  carbonate  of  copper 
before  storing  them  may  prevent  its  spread  in  the  bins. 

Leaf  Spot  (Phyllosticta  bataticola,  E.  and  M.).  —  Description. 
Sweet-potato  foliage  attacked  by  this  disease  dies  at  the  points 
of  infection,  the  dead  portions  turning  nearly  white.  The 
plants  may  suffer  severely  from  the  disease,  the  yield  being 
correspondingly  reduced. 

Treatment.  Spray  with  the  Bordeaux  mixture  at  the  first 
appearance  of  the  fungus. 

White  Mold;  Leaf  Mold  (Cystopus  IpomcecE-pandurana,  Farl.). 
—  Description.  This  fungus  causes  the  leaves  to  turn  brown, 
the  older  ones  being  particularly  affected.  Small  white  patches 
also  appear  on  the  under  side  of  the  discolored  areas. 

Treatment.  Spraying  the  vines  with  a  good  fungicide  will 
probably  prove  valuable  in  checking  the  disease. 

INSECT  ENEMIES. 

Sawfly  (Schizocerus  ebenus,  Norton;  S.  privatus,  Norton). — 
Description.  These  two  sawflies  are  not,  as  a  rule,  very  seri- 
ous, but  occasionally  they  develop  in  sufficient  numbers  to  do- 


Sweet  Potato^  Sycamore.  369 

considerable  damage.  The  larvae  appear  during  the  summer, 
and  feed  upon  the  foliage. 

Treatment.  The  same  treatment  recommended  for  the  de- 
struction of  the  currant  sawfly  will  also  destroy  these  insects. 
The  applications,  however,  need  not  begin  until  the  young 
larvae  are  noticed,  but  they  should  be  repeated  as  required 
during  the  summer. 

Tortoise  Beetles;  Golden  Bugs  (Cassidce).  —  Description.  The 
insects  hibernate  in  the  adult  state.  They  attack  the  young 
potato  vines  during  May  and  June,  eating  irregular  holes  in 
the  foliage.  Eggs  are  laid,  and  during  June  and  July  the 
larvae  appear.  At  this  time  the  vines  are  growing  so  fast  that 
the  insects  do  comparatively  little  injury.  The  adults  appear 
again  during  July  and  August,  but  no  eggs  seem  to  be  laid 
until  the  following  spring. 

Treatment.  Professor  J.  B.  Smith  recommends  the  use  of 
Paris  green  or  London  purple  at  the  rate  of  1  pound  to  175 
gallons  of  water.  The  application  should  be  made  as  soon  as 
injury  is  noticed,  both  sides  of  the  leaves  receiving  treatment. 
The  vines  should  be  treated  again  if  the  first  application  does 
not  prove  effective. 

SYCAMORE. 

Leaf  Blight  (Glceosporium  neruisequum,  Sacc.).  —  Description. 
Both  the  native  and  the  foreign  species  of  plane  trees  are  sub- 
ject to  the  attacks  of  a  fungus  which  causes  the  leaves  to  appear 
as  if  scorched.  The  disease  develops  so  early  in  the  season 
that  the  injury  caused  by  it  is  often  ascribed  to  frost.  Entire 
trees  are  frequently  discolored  by  the  abundance  of  brown  leaf 
surface,  and  although  this  form  of  the  disease  is  present  only 
about  two  months,  still  trees  have  been  killed  by  the  repeated 
attacks  of  the  fungus.  Diseased  leaves  often  fall. 

Treatment.  The  severity  of  the  attacks  can  undoubtedly  be 
diminished  by  spraying  with  fungicides  as  soon  as  the  leaves 
unfold  in  spring,  repeating  the  operation  so  that  all  new  growths 
may  be  protected.  But  such  applications  can  only  be  made  to 
smaller  trees,  and  when  they  are  impracticable  a  probable  help 
in  checking  the  malady  is  to  burn  all  affected  leaves  that  fall 
from  the  trees. 

2B 


370  The  Spraying  of  Plants. 

TOBACCO. 
INSECT  ENEMIES. 

Tobacco  worm  (Phlegethontius  Carolina,  Linn.).  —  Description. 
The  moth  closely  resembles  the  tomato  worm  as  regards  color 
and  habits.  There  are  two  broods  in  the  South,  and  it  is  here 
that  much  injury  is  done  to  the  tobacco  plantations  through 
the  ravenous  appetite  of  the  worms. 

Treatment.  The  destruction  of  the  insect  by  means  of  the 
arsenites  appears  to  be  the  most  feasible  method.  The  follow- 
ing practice  appears  to  be  safe  and  efficient : 1  "  To  those  who 
wish  to  use  poison  I  would  advise  the  use  of  (a)  Paris  green, 
|  pound  in  a  forty-gallon  barrel  of  water,  with  a  little  white- 
wash well  stirred  in.  (&)  That  the  mixture  be  kept  well  stirred 
in  the  barrel  and  sprayer,  (c)  That  applications  should  begin 
by  the  tenth  of  June  and  be  repeated  every  two  weeks  by  top- 
ping, and  that  no  applications  should  be  made  after  that  time." 
Hand  picking  may  also  be  resorted  to. 


TOMATO. 
FUNGOUS  DISEASES. 

Blight  ( Cladosporium  fulvum,  Cooke) .  —  Description.  Af- 
fected leaves  first  show  dark-brown  spots  on  the  under  side. 
The  upper  surface  at  the  same  time  turns  yellow  and  the  edges 
of  the  leaves  curl  downward,  as  a  rule.  As  the  disease  pro- 
gresses, the  foliage  shrivels  and  eventually  dies,  leaving  the 
naked  stems.  The  fungus  is  found  both  in  greenhouses  and 
out  of  doors. 

Treatment.  For  the  treatment  of  the  blight  when  found 
upon  plants  grown  under  glass,  see  GREENHOUSE  PESTS.  When 
the  fungus  appears  out  of  doors,  the  plants  should  immediately 
be  thoroughly  sprayed  with  the  Bordeaux  mixture,  or  modified 
eau  celeste,  repeating  the  treatment  at  intervals  of  ten  days  or 
two  weeks,  until  no  further  infection  is  feared. 

Rot  (Maerosporium  Tomato,  Cooke). — Description.  This 
fungus  generally  attacks  the  tomatoes  when  they  are  over  one- 
half  grown.  The  blossom  end  is  attacked,  the  appearance  of  a 
small  black  spot  being  the  first  indication  of  the  disease.  This 

i  Peter,  Ky.  Agric.  Exp.  Sta.  Bull.  53, 139. 


Tomato.  371 

spot  increases  in  size  until  fully  half  of  the  tomato  is  destroyed. 
The  diseased  part  is  black  and  sunken,  and  generally  extends 
squarely  across  the  tomato  from  side  to  side  (Fig.  91).  The 
warm  moist  weather  of  summer  appears  to  be  particularly 
favorable  to  the  development  of  this  parasite. 

Treatment.  Very  thorough  spraying  with  the  Bordeaux  mix- 
ture, or  other  copper  compound,  is  perhaps  the  best  preventive. 
If  possible,  a  dry  location  should  be  selected  for  growing  the 
plants,  and  the  stems  should  be  kept  free  from  the  ground. 


FIG.  91.  —  Tomato  rot 

Two  other  serious  diseases  of  the  tomato  are  also  known,  but 
as  they  are  probably  caused  by  bacteria,  no  remedies  can  as  yet 
be  named.  It  is  probable  that  one  of  these  organisms  is  the 
first  cause  of  the  rotting  of  tomatoes  above  described. 

INSECT  ENEMIES. 

Tomato  Worm  (Phlegethontius  celeus,  Hbn.). — Description. 
The  larvae  of  this  moth  are  fully  three  inches  in  length  when 
grown.  They  are  of  a  green  color,  but  have  a  few  nearly  white 
markings  on  each  side  of  the  body.  They  devour  an  enormous 
amount  of  foliage,  and  can  be  discovered  by  the  bare  places 
among  the  plants.  Early  in  September  the  larvae  enter  the 
ground  to  pupate,  and  here  they  remain  until  the  following 
summer,  when  the  moths  appear.  These  belong  to  the  Sphinx 


372 


The  Spraying  of  Plants. 


family,  and  they  are  beautifully  and  delicately  marked.  They 
fly  mostly  in  the  evening.  The  ground  color  is  a  soft  gray,  but 
there  are  various  markings  of  a  darker  color,  some  red  or 
reddish-brown  parts  being  present. 

Treatment.  Hand  picking  is  the  most  common  method  of 
destroying  the  larvae,  but  any  of  the  poisons  in  use  against 
chewing  insects  would  answer  the  purpose  as  well. 


TURNIP. 


INSECT  ENEMIES. 

Maggot.     See  under  CABBAGE. 


VERBENA. 
FUNGOUS  DISEASES. 

Mildew ;  Rust  (Erysiphe  Cichoracearum,  DC.,  or  Oidium  ery- 
'iphoides,  Fr.).     See  under  CUCUMBER. 


FUNGOUS  DISEASES. 


VIOLET. 


Mildew.     See  under  PANSY. 

Rust;   Spot;  Violet  Disease 

(Cercospora  Violce,  Sacc.). — All 
violet  growers  are  familiar 
with  this  disease  (Fig.  92), 
which  causes  the  formation 
upon  violet  foliage  of  small, 
circular,  grayish  -  white  spots 
having  a  dark  center.  The 
first  appearance  of  the  disease 
may  occur  during  summer, 
while  the  plants  are  in  the 
open  ground.  Or  it  may  not 
be  visible  until  late  in  win- 
ter. Surrounding  conditions 
appear  to  have  a  strong  influ- 
ence in  the  development  of  the 
fungus.  Too  much  heat,  care- 
lessness in  watering,  fresh  stable  manure,  and  improper  ven- 
tilation have  all  been  advanced  as  immediate  causes  of  the 


FIG.  92.  —Violet  disease. 


Violet,   Willow.  373 

appearance  of  the  disease.  Much  truth  undoubtedly  lies  in 
these  statements,  and  the  requirements  of  the  plants  should  be 
thoroughly  understood  by  all  who  attempt  to  grow  the  crop. 

Treatment.  Give  good  culture.  If  the  disease  persists,  spray 
the  plants  with  a  good  fungicide,  as  the  Bordeaux  mixture, 
making  the  first  application  as  soon  as  the  disease  appears, 
and  repeating  it  at  intervals  of  two  to  four  weeks.  Destroy 
affected  leaves  and  plants. 

WATERMELON. 
FUNGOUS  DISEASES. 

Anthracnose.  —  This   disease  may  be  identical  with  the  an- 
thracnose  of  the  BEAN,  which  see. 
Powdery  Mildew.     See  under  MUSKMELON. 

WEIGELIA. 
INSECT  ENEMIES. 

Four-lined  Leaf -bug.     See  under  CURRANT. 

WHEAT. 
FUNGOUS  DISEASES. 

Stinking  Smut  (Tilletia  fceteus,  Schroet.;  and  T.  Tritici 
Wint.). —  Description.  This  disease  causes  the  wheat  kernels 
to  become  swollen  as  they  approach  maturity.  They  are  at 
first  green  in  color,  but  later  turn  grayish-brown.  If  a  kernel 
is  crushed,  it  will  be  found  to  be  filled  with  a  brown  powder 
possessing  a  very  disagreeable  odor :  this  has  been  the  cause  of 
the  popular  name  of  the  disease. 

Treatment.     See  under  OATS. 

Loose  Smut  (Ustilago  Tritici,  Jensen).  —  Description.  This 
disease  closely  resembles  the  loose  smut  of  oats.  Unfortunately, 
no  practical  remedies  are  as  yet  known. 


WILLOW. 
INSECT  ENEMIES. 

Willow-worm;    Antiopa  Butterfly    (Vanessa  Antiopa,  Linn.). 
-  Description.     The  adult  insect  hibernates  during  the  winter. 


374  The  Spraying  of  Plants. 

It  is  a  butterfly  whose  wings  are  "purplish  brown  above,  with  a 
broad  buff-yellow  margin,  near  the  inner  edge  of  which  there 
is  a  row  of  pale  blue  spots.  Expands  from  three  to  three  and 
a  quarter  inches."1  The  eggs  are  laid  early  in  spring  upon 
willow,  poplar,  and  elm  trees,  the  young  larvae  appearing  early 
in  June.  When  full  grown  the  larvae  are  nearly  two  inches  in 
length ;  the  ground  color  is  black,  but  it  is  relieved  by  spots 
of  white  and  red.  During  June  the  larvae  pupate,  the  adult 
appearing  early  in  July.  There  are  two  broods  each  year,  the 
larvae  of  the  second  appearing  in  August. 

Treatment.     The  caterpillars  are  voracious  feeders,  and  they 
may  be  destroyed  by  arsenical  poisons. 

*  Harris,  "Insects  of  Mass.  Injurious  to  Vegetation,"  1841,  218. 


APPENDIX. 


A.  LAWS  REGARDING  THE  SPRAYING  OF  PLANTS. 

Many  of  the  organisms  which  attack  cultivated  plants  have 
become  so  abundant  and  serious  in  certain  localities  that  com- 
munities have  taken  measures  to  check  the  spread  of  existing 
parasites,  and  also  to  prevent  the  introductions  of  different  ones 
which  occur  in  other  localities.  A  few  States  have  passed  quar- 
antine laws  with  this  end  in  view,  all  nursery  stock  being  rigidly 
examined,  and  treated  if  necessary,  before  its  passage  into  the 
State  is  allowed.  The  exportation  of  trees,  etc.,  from  very  re- 
stricted areas  within  certain  States  has  also  been  forbidden. 
The  suppression  of  insect  and  fungous  diseases  is  thus  rapidly 
increasing  in  importance,  and  laws  aiming  at  their  extermina- 
tion are  being  more  and  more  frequently  passed.  Several  of 
these  consider  the  spraying  of  plants,  and  below  will  be  found 
the  leading  points  concerning  these  acts. 

CALIFORNIA  has  been  a  pioneer  in  legislating  against  plant 
diseases.  On  March  14,  1881,  there  was  approved  "An  Act 
to  Protect  and  Promote  the  Horticultural  Interests  of  the 
State."  It  was  amended  by  an  act  approved  March  19,  1889, 
and  by  an  act  approved  March  31,  1891.  Section  1  states : 
"  Whenever  a  petition  is  presented  to  the  Board  of  Supervisors 
of  any  county,  and  signed  by  twenty-five  or  more  persons  who 
are  resident  freeholders  and  possessors  of  an  orchard,  or  both, 
stating  that  certain  or  all  orchards  or  nurseries,  or  trees  of  any 
variety  are  infested  with  scale  insects  of  any  kind  injurious  to 
fruit,  fruit  trees,  and  vines,  codlin-moth,  or  other  insects  that 
are  destructive  to  trees,  and  praying  that  a  commission  be 

375 


376  Appendix. 

appointed  by  them,  whose  duty  it  shall  be  to  supervise  theii 
destruction  as  herein  provided,  the  Board  of  Supervisors  shall, 
within  twenty  days  thereafter,  select  three  commissioners  for 
the  county  to  be  known  as  a  '  County  Board  of  Horticultural 
Commissioners.'  .  .  ."  [Statutes  of  California,  1889,  413.] 

It  is  the  duty  of  the  County  Board  to  cause  the  inspection  of 
all  plantations  and  buildings  in  which  the  presence  of  injurious 
insects  or  fungi  is  feared.  If  such  are  found,  a  notice  is  served 
upon  the  proper  individuals,  and  it  then  becomes  incumbent 
upon  the  latter  to  destroy  the  pest.  In  case  this  is  not  done 
within  a  certain  period,  the  Board  is  compelled  to  assume  the 
work,  the  expenses  being  ultimately  drawn  from  the  owners  of 
the  property.  An  excellent  feature  of  the  above  law  is  that  all 
officials  are  required  to  enforce  its  provisions,  as  is  distinctly 
stated.  The  mere  granting  of  power  to  act  in  a  certain  man- 
ner has  been  fatal  to  the  enforcement  of  other  laws  of  this 
nature. 

Several  counties  have  availed  themselves  of  the  benefits  to  be 
derived  from  the  above  acts,  and  have  passed  ordinances  suited 
to  their  needs.  In  1894,  thirty-four  counties  possessed  "  Horti- 
cultural Quarantine  Guardians." 

CANADA  possesses  a  law  which  prohibits  spraying  fruit  trees 
while  in  bloom  with  any  substance  injurious  to  bees.  The  act 
was  passed  in  April,  1892,  and  reads  as  follows : 

"  1.  No  person  in  spraying  or  sprinkling  fruit  trees  during 
the  period  within  which  such  trees  are  in  full  bloom  shall  use, 
or  cause  to  be  used,  any  mixture  containing  Paris  green  or  any 
other  poisonous  substance  injurious  to  bees. 

"2.  Any  person  contravening  the  provisions  of  this  Act, 
shall  on  summary  conviction  thereof  before  a  justice  of  the 
peace,  be  subject  to  a  penalty  of  not  less  than  $1.00  or  more 
than  $5.00  with  or  without  costs  of  prosecution,  and  in  case  of 
a  fine  or  a  fine  and  costs  being  awarded,  and  of  the  same  not 
being  upon  conviction  forthwith  paid,  the  justice  may  commit 
the  offender  to  the  common  gaol,  there  to  be  imprisoned  for  any 
term  not  exceeding  thirty  days  unless  the  fine  and  costs  are 
sooner  paid. 

"3.  This  Act  shall  not  come  into  force  until  the  first  day  of 
January,  1893." 


Appendix.  377 

This  law  scarcely  appears  necessary,  as  all  our  fruits  may  be 
amply  protected  without  treating  them  during  the  blossoming 
period ;  and,  bees  unquestionably  suffer  if  such  applications 
are  made. 

The  MASSACHUSETTS  legislature,  on  March  14, 1890,  approved 
an  act  whereby  the  Governor  was  "  authorized  to  appoint  a 
commission  to  provide  and  carry  into  execution  all  possible  and 
reasonable  measures  to  prevent  the  spreading,  and  secure  the 
extermination  of  the  Ocneria  dispar  or  gypsy  moth,  in  this 
Commonwealth."  Three  commissioners  were  appointed,  and 
work  was  begun  April  1st. 

In  1891,  by  an  act  approved  April  17th,  the  entire  work 
came  under  the  control  of  the  State  Board  of  Agriculture. 
Spraying  with  Paris  green  was  one  of  the  methods  adopted  for 
the  extermination  of  the  insect.  "  "When  the  caterpillars  ap- 
peared, spraying  was  commenced  with  a  large  force  of  men  and 
teams  equipped  with  hogsheads  of  Paris  green  and  water, 
pumps,  hose,  ladders,  oil  suits,  etc.  —  an  extensive  and  expen- 
sive outfit."  l  The  remedy  proved  to  be  only  partially  success- 
ful, however,  as  it  was  expensive,  and  it  met  the  opposition  of 
property  owners.  The  large  size  of  many  of  the  plants  also 
prevented  proper  applications  from  being  made,  so  that  the 
treatments  have  since  met  with  little  favor. 

MICHIGAN  passed  a  compulsory  spraying  law  early  in  1895. 
It  is  entitled,  "  An  Act  to  Prevent  the  Spreading  of  Bush,  Vine, 
and  Fruit  Tree  Pests,  such  as  Canker  Worms  and  Other  Insects, 
and  Fungous  and  Contagious  Diseases,  and  to  Provide  for  their 
Extirpation." 

The  more  important  features  of  the  law  are  here  outlined : 
"Section  1.  The  people  of  the  state  of  Michigan  enact  that 
it  shall  be  the  duty  of  every  owner,  possessor,  or  occupier  of 
an  orchard,  nursery,  or  vineyard,  or  of  land  where  fruit  trees  or 
vines  are  grown,  within  this  state,  to  spray  with  a  poisonous 
solution  or  disinfectant  of  sufficient  strength  to  destroy  such 
injurious  insects  or  contagious  diseases,  all  fruit  trees  or  vines 
grown  on  such  lands  which  may  be  infested  with  any  injurious 
insects  or  worms,  or  infected  with  any  contagious  disease  known 

1  Special  Report  of  the  Mass.  State  Bd.  of  Agric.  Jan.  1892,  7. 


378  Appendix. 

to  be  injurious  to  fruit  or  fruit  trees  or  vines :  Provided,  That 
no  such  spraying  shall  be  done  while  said  fruit  trees  or  vines 
are  in  blossom,  except  in  case  of  canker-worms. 

"Section  2.  In  any  township  in  this  state  where  such  inju- 
rious insects  or  contagious  diseases  are  known  to  exist,  or  in 
which  there  is  good  reason  to  believe  they  exist,  or  danger  may 
be  justly  apprehended  of  their  introduction,  it  shall  be  the  duty 
of  the  township  board,  upon  the  petition  of  at  least  ten  free- 
holders of  such  township,  to  appoint  forthwith  three  competent 
freeholders  of  said  township,  as  commissioners,  who  shall  hold 
office  during  the  pleasure  of  the  board,  and  such  order  of  ap- 
pointment and  of  revocation  shall  be  entered  at  large  upon  the 
township  record.  Provided,  That  in  townships  having  a  board 
of  yellows  commissioners,  such  commissioners  shall  be  ex  officio 
commissioners  under  this  act." 

It  is  the  duty  of  the  commissioners  to  notify  owners  of  plan- 
tations of  the  presence  of  any  injurious  parasite,  it  being  un- 
necessary that  a  complaint  be  first  made  by  any  one. 

"  Section  5.  Whenever  any  person  shall  refuse  or  neglect  to 
comply  with  the  order  to  spray  or  disinfect  the  orchards  or 
vineyard  designated  by  the  commissioners,  as  aforesaid,  it 
shall  become  the  duty  of  the  commissioners  to  cause  said  trees 
or  vines  to  be  effectually  sprayed  with  a  poisonous  solution,  or 
disinfected,  as  occasion  should  require,  forthwith,  employing 
all  necessary  aid  for  that  purpose,  and  the  expenses  for  the 
same  shall  be  a  charge  against  the  township;  and  for  said 
spraying  or  disinfecting,  the  said  commissioners,  their  agents 
or  workmen,  shall  have  the  right  and  power  to  enter  upon  any 
and  all  premises  within  their  township. 

"  Section  6.  If  any  owner,  township  officer,  or  commissioner, 
neglects  or  refuses  to  comply  with  the  requirements  of  this  law 
as  set  forth  in  the  preceding  sections,  and  within  the  time 
therein  specified,  such  persons  shall  be  deemed  guilty  of  a  mis- 
demeanor, and  punished  by  fine  not  exceeding  fifty  dollars  or 
imprisonment  in  the  county  jail  not  exceeding  sixty  days,  or 
by  both  such  fine  and  imprisonment,  in  the  discretion  of  the 
court ;  and  any  justice  of  the  peace  of  the  township  where 
such  trees  or  vines  may  be  growing  shall  have  jurisdiction 
thereof." 

The  act  was  ordered  to  take  immediate  effect. 


Appendix.  379 

OREGON  has  followed  the  example  of  California,  for  on  Feb- 
ruary 25,  1889,  the  legislature  approved  "  An  Act  to  Create  a 
State  Board  of  Horticulture  and  Appropriate  Money  Therefor." 
It  was  amended  February  21, 1891,  and  again  in  February,  1895. 
After  dwelling  upon  the  formation  of  a  "Board  of  Horticul- 
ture," and  other  details  of  organization,  etc.,  some  of  the  powers 
of  the  board  are  stated  as  follows : 

"  Section  VI.  For  the  purpose  of  preventing  the  introduction 
into  the  State,  or  spread  of  contagious  diseases,  insect  pests,  or 
fungous  growth  among  fruit  or  fruit  trees,  and  for  the  preven- 
tion, treatment,  cure,  and  extirpation  of  fruit  pests,  and  diseases 
of  fruit  and  fruit  trees,  and  for  the  disinfection  of  grafts,  cions, 
orchard  debris,  fruit  boxes  and  packages,  and  other  material  or 
transportable  articles  dangerous  to  orchards,  fruit  or  fruit  trees, 
said  Board  may  make  regulations  for  the  quarantining,  inspec- 
tion, and  disinfection  thereof,  which  said  regulations  shall  be 
circulated  by  the  Board  in  printed  form  among  the  fruit  grow- 
ers and  fruit  dealers  of  the  State,  shall  be  published  at  least  four 
successive  times  in  some  daily  or  weekly  paper  in  each  county 
in  the  State,  before  the  same  shall  be  in  force  therein,  and  shall 
be  posted  in  three  conspicuous  places  in  each  county  in  the 
State,  one  of  which  shall  be  at  the  County  Court  House. 
Such  regulations,  when  so  promulgated,  shall  be  held  to  im- 
port notice  of  their  contents  to  all  persons  within  the  State, 
and  shall  be  binding  upon  all  persons  therein.  A  wilful  vio- 
lation of  any  quarantine  or  other  regulation  of  said  Board, 
necessary  to  prevent  the  introduction  into  the  State,  or  the 
shipment  sale  or  distribution  of  any  articles  so  infected  as  to 
be  dangerous  to  the  fruit  growing  interest  of  the  State,  or  the 
spread  of  dangerous  diseases  among  fruit  trees  or  orchards, 
shall  be  deemed  a  misdemeanor,  and  on  conviction  thereof, 
shall  be  punished  by  a  fine  of  not  less  than  five,  nor  more  than 
one  hundred  dollars,  for  each  offense,  or  by  fine  and  imprison- 
ment for  not  less  than  five  nor  more  than  thirty  days." 

When  the  Board  becomes  aware  of  the  presence  of  injurious 
insects  or  fungi  upon  certain  premises,  the  owner  is  to  be  noti- 
fied. 

"  Such  notice  shall  contain  directions  for  the  application  of 
some  treatment  approved  by  the  Commissioners  for  the  eradica- 
tion or  destruction  of  said  pests,  or  the  eggs  or  larvae  thereof,  or 


380  Appendix. 

the  treatment  of  contagious  diseases  or  fungous  growths.  Any 
and  all  such  places,  orchards,  nurseries,  trees,  plants,  shrubs, 
vegetables,  vines,  fruit,  or  articles  thus  infested  are  hereby 
declared  to  be  a  public  nuisance.  And  whenever  any  such 
nuisance  shall  exist  at  any  place  in  the  State,  on  the  property  of 
any  owner  or  owners,  upon  whom  or  upon  the  person  in  charge 
or  possession  of  whose  property,  notice  has  been  served  as  afore- 
said, and  who  shall  have  failed  or  refused  to  abate  the  same 
within  the  time  specified  in  such  notice,  or  on  the  property  of 
any  non-resident  or  any  property  not  in  the  possession  of  any 
person  and  the  owner  or  owners  of  which  cannot  be  found  by 
the  resident  member  of  the  Board  or  the  Secretary,  after  diligent 
search  within  the  district,  it  shall  be  the  duty  of  the  Board,  or 
the  members  thereof  in  whose  district  said  nuisance  shall  exist, 
or  the  Secretary  under  his  or  their  direction,  to  cause  such 
nuisance  to  be  at  once  abated,  by  eradicating  or  destroying  said 
insects  or  pests,  or  their  eggs  or  larvae,  or  by  treating  or  disin- 
fecting the  infested  or  diseased  articles.  The  expense  thereof 
shall  be  a  County  charge,  and  the  County  court  shall  allow  and 
pay  the  same  out  of  the  general  fund  of  the  County." 

UTAH  possesses  a  law  which  might  be  of  considerable  value. 
It  was  approved  March  8,  1894,  and  is  known  as 

"  An  Act  Authorizing  the  County  Courts  to  Appoint  Fruit 
Tree  Inspectors  and  to  Provide  for  the  Destruction  of  Fruit 
Destroying  Insects." 

Its  directions  are  specific,  and  so  complete  that  if  the  county 
probate  judges  perform  their  duty  properly,  the  plants  should 
remain  very  free  from  parasites.  The  following  extract  shows 
to  what  extent  details  are  mentioned  : 

"  Section  1.  It  shall  be  the  duty  of  the  county  court  of  any 
county  in  the  Territory  of  Utah  where  fruit  is  grown,  to  appoint 
one  or  more  fruit  tree  inspectors  for  such  county. 

"  Sec.  2.  The  duty  of  the  fruit  tree  inspector  of  each  county 
shall  be  to  inspect  every  orchard,  vineyard  or  nursery  in  such 
county  at  such  time  and  under  such  regulations  as  the  county 
court  shall  prescribe.  He  shall  annually  report  to  the  county 
court  every  item  of  interest  and  the  result  of  his  labors  pertain- 
ing to  the  duties  of  his  office. 

*  Sec.  3.     It  shall  be  the  duty  of  the  Probate  Judge  of  any 


Appendix.  381 

county  wherein  fruit  trees  are  growing,  to  annually  issue  his 
proclamation,  stating  the  time  or  times  when  it  is  prudent  and 
proper  to  spray  fruit  trees  and  to  otherwise  disinfect  orchards 
that  are  infested  with  any  kind  of  fruit-destroying  insects,  in 
which  he  shall  name  two  or  more  formulas  that  have  been  used 
and  approved  for  such  purposes." 

And  further : 

"  Sec.  5.  The  county  court  is  hereby  authorized  and  required 
to  provide  for  the  publication  of  the  proclamation  required  by 
section  3,  and  to  formulate  such  rules  and  regulations  as  it  may 
deem  proper,  to  govern  the  actions  of  the  fruit  tree  inspector  in 
his  duties,  and  to  give  such  public  notice  as  it  may  deem  proper 
in  relation  to  the  disinfecting  of  storerooms,  warehouses  and 
salesrooms  where  fruits  in  either  a  green  or  dried  state  may  be 
stored,  handled  or  offered  for  sale." 

On  March  8,  1895,  a  proclamation  issued  by  the  probate 
judge  of  Sanpete  County  contained  directions  for  spraying 
apple,  pear,  peach,  and  plum  trees,  the  time  for  making  the 
applications  as  well  as  the  materials  to  be  used  being  stated. 

An  inquiry  was  made  to  learn  of  the  success  attending  the 
enforcement  of  the  terms  of  the  proclamation,  and  of  the  gen- 
eral effectiveness  of  the  act  as  passed  by  the  legislature.  Mr. 
Joseph  Judd,  the  probate  judge  of  Sanpete  County,  replied  as 
follows : 

"  In  answer  to  your  favor  on  the  subject  of  our  spraying  laws,  will  say  we  have 
the  law  on  our  statute  book,  and  it  was  enforced  in  1894.  It  has  been  carried  out 
thoroughly  this  year  again,  and  we  have  found  good  results  of  the  spraying.  There 
is  no  doubt  that  spraying  is  absolutely  necessary  in  these  dry  climates,  and  I  con- 
sider it  a  very  necessary  law.  But  I  have  always  doubted  its  constitutionality,  as 
it  hardly  looks  reasonable  that  the  law  can  tell  a  person  just  how  and  when  he  shall 
spray  or  otherwise  treat  his  orchard,  and  inflict  a  penalty  if  the  law  is  not  complied 
with. 

"  Some  of  our  people  have  refused  to  comply  in  full,  or  as  to  when  they  shall 
spray,  and  we  have  just  had  a  ruling  on  the  law  by  our  chief  justice  Merritt.  He 
declares  the  law  unconstitutional,  and  from  this  time  on  I  think  that  spraying  will 
not  be  done  so  generally." 

With  such  a  precedent,  it  appears  doubtful  if  laws  designed 
to  control  spraying  will  ever  become  popular. 


382 


Appendix. 


B.  METRIC   SYSTEM. 

The  meter  is  the  primary  unit  of  length.  It  is  equal  to 
ToooWfftfth  part  of  the  distance  measured  on  a  meridian  of 
the  earth  from  the  equator  to  the  pole,  and  equals  about  39.37 
inches. 


MEASURES  OF  LENGTH. 

EQUIVALENTS. 

Myriameter 

10,000        meters 

6.213T    miles 

Kilometer 

1,000 

j     0.62137  mile,  or 
1     8280  ft.  10  in. 

Hectometer 

100 

828  ft.  1  in. 

Dekameter 

10 

393.7  in. 

Meter 

1        meter 

39.37  in. 

Decimeter 

.1 

3.937  in. 

Centimeter 

.01       " 

.3937  in. 

Millimeter 

.001     " 

.03937  in. 

MEASUEES  OF  SURFACE. 

EQUIVALENTS. 

Hectare                                           10,000  sq.  meters 
Are                                                          100  " 
Centare                                                  1  "  meter 

2.471  acres 
119.6  sq.  yards 
1550.  sq.  inches. 

MEASURES  OF  CAPACITY. 


No.  OF 
LITERS. 

CUBIC  MEASURE. 

DRY  MEASURE. 

LIQUID  OR  WINE 
MEASURE. 

Kiloliter,  or  Stere 

1000 

1  en.  meter 

1.308  cu.  yards 

264.17  gal. 

Hectoliter 

100 

.1" 

2  bu.  3.35  pks. 

26.417  gal. 

Dekaliter 

10 

10  cu.  decimeters 

9.08  quarts 

2.6417  gal. 

Liter 

1 

1  cu.  decimeter 

.909  quart 

1.0567  qts. 

Deciliter 

.1 

.1  "          " 

6.1022  cu.  inches 

.845  gill 

Centiliter 

.01 

10  cu.  centimeters 

.6102  cu.  inch 

.338  fl.  oz. 

Milliliter 

.001 

.1  cu.  centimeter 

.061     "      " 

.27  fl.  dram 

EQUIVALENTS. 


Appendix. 


383 


SYSTEM  OF  WEIGHTS. 

EQUIVALENTS. 

No.  OF  GRAMS. 

WEIGHT  OF  WATER 
MAXIMUM  DENSITY. 

AVOIRDUPOIS 
WEIGHT. 

Millier,  or  Tonneau 

1,000,000 

1     cu.  meter 

2204.6    pounds 

Quintal 

100,000 

1     hectoliter 

220.46 

Myriagram 

10,000 

1     dekaliter 

22.046      " 

Kilogram,  or  Kilo 

1,000 

1     liter 

2.2046    " 

Hectogram 

100 

1     deciliter 

3.5274  oz. 

Dekagram 

10 

10     cu.  centimeters 

.3527  " 

Gram 

1 

1     cu.  centimeter 

15.432    grains 

Decigram 

.1 

.1   " 

1.5432      " 

Centigram 

.01 

10    cu.  millimeters 

.1543  grain 

Milligram 

.001 

1      "    millimeter 

.0154      " 

COMMON 
MEASURE. 

EQUIVALENTS. 

COMMON 
MEASURE. 

EQUIVALENTS. 

An  inch 

2.54  centimeters 

A  cu.  yard 

.7646  cu.  meter 

Afoot 

.3048  meter 

A  cord 

3.624  steres 

A  yard 

.9144      " 

A  liquid  qt. 

.9465  liter 

A  rod 

5.029  meters 

A  gallon 

3.786  liters 

A  mile 

1.6093  kilometers 

A  dry  qt. 

1.101     " 

A  sq.  inch 

6.452  sq.  centimeters 

A  peck 

8.811     " 

A  "    foot 

.0929  sq.  meter 

A  bushel 

35.24       " 

A  "    yard 

.8361   "        " 

An  oz.  avoirdupois 

28.35  grams 

A  "   rod 

25.29  sq.  meters 

A  pound        " 

.4536  kilogram 

An  acre 

.4047  hectare 

A  ton 

.9072  tonneau 

A  sq.  mile 

259  hectares. 

A  grain  troy 

.0648  gram 

A  cu.  inch 

16.39  cu.  centimeters 

An  oz.      " 

31.104  grams 

A    "  foot 

.02832  cu.  meter 

A  pound  " 

.3732  kilogram 

INDEX. 


Acetate  of  copper,  137. 

Aceto-arsenite  of  copper,  121. 

Acme  nozzle,  204. 

Aconite,  16. 

Acrobasis  Vaccinii,  280. 

Actinonema  Jtosce,  358. 

Action  of  insecticides  and  fungicides, 
225-238. 

Adhesive  power  of  fungicides,  47. 

Algeria  tipuliformis,  286. 

Agitators,  211-213. 

Air-chambers,  210,  211. 

Air-slaked  lime,  chemistry  of,  156. 

Albrand,  knapsack  pump,  187, 188. 

Alcohol,  9,  13,  115 ;  amylic,  50. 

Aletia  argillacea,  277. 

Aleyrodes,  sp.,  321. 

Alkali  and  oil  wash,  161. 

Almond  disease,  239  :  leaf  blight,  239. 

Aloes,  12,  50 ;  and  soda,  172. 

Alum  and  calcium  chloride,  44 ;  pyreth- 
rum,  116. 

Alwood,  W.  B.,  quoted,  69,  70. 

American  Ball  Nozzle  Co.,  mentioned, 
202. 

Ammonia,  116;  and  brass,  207,  208. 

Ammoniacal  copper  carbonate,  advan- 
tages of,  139 ;  and  arsenites,  136,  140 ; 
and  Paris  green,  106 ;  introduction  of, 
into  America,  101 ;  preparation  of,  13S  ; 
recommended,  108. 

Ammoniated  copper  fungicides,  30  ;  cop- 
per sulphate,  117 ;  and  ammonium 
carbonate,  160. 

Ammonium  carbonate  and  ammoniated 
copper  sulphate,  160 ;  and  copper  car- 
bonate, 140,  141 ;  copper  sulphate,  151  ; 
cupric  hydroxide,  140 ;  sulphate,  44 ; 
and  Bordeaux  mixture,  48 ;  and  copper 
sulphate,  35. 

2  r  3 


Amylic  alcohol,  50. 

Analyses,  miscellaneous,  117. 

Analysis  of  sprayed  grapes,  232,  233. 

Anhydrous  copper  sulphate,  143. 

Anisopteryx  pometaria,  249,  251. 

Anisota  rubricunda,  312. 

Anthonomus  guadrig-ibbus,  255,  256. 

Anthracnose,  bean,  261-263;  carnation, 
271 ;  currant,  285 ;  eggplant,  290 ; 
grape,  294,  see  also  grape  anthracnose ; 
raspberry,  355;  spinach,  363;  water- 
melon, 261,  373. 

Antiopa  butterfly,  373. 

Ants,  destruction  of,  57, 135. 

Aphis,  10,  308 ;  apple,  247  ;  black,  peach, 
332;  Brassicce,  267;  cabbage,  267; 
destruction  of,  12;  Cucumeris,  283; 
Mali,  247 ;  Persicw-niger,  332;  woolly, 
10. 

Apple  aphis,  247 ;  bitter  rot,  240 ;  black 
rot,  241 ;  borers,  248 ;  brown  rot,  241 ; 
bud-moth,  248  ;  canker-worm,  249,  251 ; 
case-worm,  251,  252  ;  cigar-case-bearer, 
251,  252 ;  codlin-moth,  252-255 ;  coleo- 
phora,  64  ;  curculio,  255,  256 ;  spraying 
for,  69  ;  enemies  and  diseases,  240-260 ; 
fall  web-worm,  256;  leaf  blight,  first 
treated  in  America,  88;  leaf-skeleton- 
izer,  257 ;  maggot,  257  ;  oyster-shell 
bark -louse,  258 ;  powdery  mildew,  241 ; 
railroad-worm,  257  ;  ripe  rot,  240  ;  rust, 
242  ;  scab,  243-247  ;  scab,  first  treated 
in  America,  88;  scab,  treatment  of, 
101 ;  sprayed  with  arsenites,  231 ;  tent 
caterpillar,  258  ;  value  of  spraying,  237  ; 
woolly  aphis,  259. 

Apricot,  curculio,  260;  enemies  and  dis- 
eases, 260 ;  leaf  rust,  260. 

Aqua  ammonia,  116. 

Aquarius,  pump,  190. 


386 


The  Spraying  of  Plants. 


Arsenate  of  lead,  120  ;  experiments  with, 
77 ;  preparation  of,  77 ;  soda,  120 ;  soda, 
experiments  with,  77. 

Arsenic,  117;  compared  with  arsenites, 
76 ;  early  use  of,  56,  75 ;  effect  of,  on 
vegetation,  120 ;  trioxide,  117. 

Arsenicals  and  resin  compounds,  136, 169. 

Arsenious  acid,  117  ;  anhydride,  117. 

Arsenite  of,  copper,  120 ;  lime,  128  ;  prep- 
aration of,  77,  119. 

Arsenites  and  ammoniacal  copper  car- 
bonate, 136,  140;  glue,  147;  kerosene 
emulsion,  155;  lime,  76,  77, 105;  plum 
curculio.  68-74 ;  soap,  preparation  of, 
170 ;  comparison  of,  76 ;  danger  of 
their  use,  231 ;  in  England,  66 ;  France, 
53 ;  soil,  236. 

Artipus  Floridanus,  321. 


Asparagus  beetle,  260. 

Aspidiotus  perniciosus,  828. 

Aster,  leaf  rust,  260. 

Atkinson,  G.  F.,  mentioned,  277 ;  quoted, 

271-273. 

Audoynaud,  quoted,  30. 
Australasia,  spraying  in,  57. 
Automatic  cleaning  nozzle,  200. 

Bacterial  blight,  potato,  849 ;  disease  of 

pear,  334. 
Bailey,  L.  H.,  mentioned,  199;  quoted, 

111,236,251,355,868. 
Bailey  nozzle,  200. 
Ball  nozzle,  202. 
Balm  of  Gilead,  leaf  rust,  261. 
Balsam  of  fir  and  kerosene  emulsion,  156. 
Barley,  affected  by  copper  salts,  237  ;  dis- 
eases, 261 ;  rust,  819. 
Barnard  nozzle,  203. 
Barnard,  W.  8.,  mentioned,  202,  203; 

suggested  kerosene  emulsion,  82. 
Baron,  Le,  quoted,  61,  62. 
Barrel  machine,  191 ;  pumps,  209-220. 
Barry,  P.,  quoted,  13. 
Beach,  8.  A.,  quoted,  263. 
Bean,  anthracnose,  261-268  ;  enemies  and 

diseases,  261-263;    lima,  blight,  264; 

new,  nozzle,  199 ;  pod  rust,  261-263 ; 

rust,  263 ;  weevil,  263. 
Beans,  affected  by  copper  salts,  235,  237. 
Bean-Chamberlin  M'f  g  Co.,  mentioned, 

192. 
Bean's  cyclone  nozzle,  204. 


Beaum6,  scale  of,  116, 117. 

Beaune,  treatment  of,  24,  29. 

Bees,  poisoning  by  sprays,  law  regard- 
ing, 376. 

Beet,  diseases,  264,  265;  leaf  spot,  264; 
root  rot,  264;  rust,  265;  treatment, 
101 ;  scab,  265. 

Belknap  Co.,  mentioned,  199. 

Bellows,  204,  205 ;  for  atomizing  liquids, 
186. 

Bencker,  G.,  quoted,  44. 

Benzine,  125;  emulsion  (Italian),  145. 

Berrichone  mixture,  tested,  48. 

Bessey,  C.  E.,  quoted,  65-67. 

B.  F.  J.,  quoted,  98. 

Bidault,  quoted,  24. 

Bird's-eye  rot,  grape,  294-296. 

Bisulphide  of  carbon,  52,  134 ;  emulsion 
(Italian),  145 ;  injector,  135. 

Bitter  rot,  apple,  240 ;  grape,  305 ;  gourd, 
5. 

Black  aphis,  peach,  332. 

Blackberry,  266 ;  see  also  Kaspberry ; 
anthracnose,  101. 

Blackhead,  cranberry,  280. 

Black  knot,  and  kerosene,  106;  cherry, 
275:  plum,  340;  treatment  of,  111, 
112. 

Black-lined  plant-bug,  287. 

Black  rot,  apple,  241;  grape,  297-300; 
early  treatment  of,  89  ;  in  France,  39 ; 
quince,  353 ;  sweet  potato,  368 ;  spot, 
peach,  327  ;  rose,  358. 

Blight,  bacterial,  of  potato,  349 ;  carna- 
tion, 273 ;  celery,  274 ;  early,  of  potato, 
845;  fire,  pear,  334;  leaf,  plum,  339; 
quince,  353 ;  lima  bean,  264 ;  twig, 
peach,  328  ;  potato,  347 ;  powder,  174 ; 
privet,  352  ;  quince,  334,  353  ;  tomato, 
870. 

Blue  stone,  142 ;  vitriol,  142. 

Bones,  burnt,  6. 

Borate  of  soda ;  see  Sodium  borate. 

Borax,  125. 

Bordeaux  mixture,  agitation  of,  132  ;  and 
amount  of  lime  required,  128 ;  air- 
slaked  lime,  30 ;  ammonium  sulphate, 
48;  carbonic  acid  gas,  127;  ferrocy- 
anide  of  potassium,  128,  129;  glue, 
28,  44,  48 ;  kerosene,  136 ;  kerosene 
emulsion,  156 ;  London  purple,  105 ; 
molasses,  43,  131,  133 ;  potassium  fer- 
rocyanide,  46;  resin  washes,  136;  as 


Index. 


387 


an  insecticide,  109, 133 ;  Cavazza's,  131 ; 
celeste,  formula  for,  42  ;  celeste,  tested, 
44,  48 ;  chemistry  of.  125-128  ;  dried, 
144 ;  early  method  of  applying,  181 ; 
excess  of  lime,  41 ;  first  formula  for, 
2T,  28,  81,  34,  38 ;  formula  for,  104 ;  in 
1888,  38;  Australia,  5T;  England,  55; 
injury  to  grapes,  232,  233  ;  injurious  to 
sheep,  234 ;  introduction  into  America, 
90,  92,  101 ;  normal,  108,  130 ;  origin 
of,  24;  preparation  of,  125-133;  stan- 
dard, 108,  130;  suggested  for  other 
plant  diseases  in  America,  91 ;  tested, 
48;  with  dissolved  copper,  41,  42; 
nozzle,  199,  210. 

Borer,  apple,  248;  cane  of  raspberry, 
357  ;  currant,  286 ;  imported  currant, 
286 ;  peach,  332 ;  pear,  248,  335  ;  plum, 
248,343. 

Boss  nozzle,  199. 

Bouchard,  A.,  treatment  of,  35. 

Bouillie  berrichonne,  37 ;  bordelaise,  see 
Bordeaux  mixture  ;  bordelaise  celeste 
a  poudre  unique,  48 ;  bourguignonnes, 
32 ;  dauphinoise,  35. 

Bourguignonne  mixture,  tested,  48. 

Bowers,  J.  L.,  mentioned,  69. 

Brass,  for  pumps,  207,  208. 

Bridgeman,  T.,  quoted,  13. 

Brimstone,  6,  12. 

Broom  for  applying  Bordeaux  mixture, 
1S1 ;  improved,  182. 

Brown  rot,  apple,  241 ;  cherry,  274 ; 
grape,  300-302  ;  peach,  328 ;  plum, 
339. 

Brown  turtle  insect,  10. 

JBruchus  obtectus,  263;   Pisi,  326. 

Bucket  pump,  early  use  of,  190  ;  pumps, 
208,  209. 

Budd,  J.  L.,  mentioned,  65,  66 ;  quoted, 
63. 

Bud-moth,  apple,  248;  pear,  248,  335; 
plum,  248,  343. 

Buhach,  79  ;  preparation,  163,  164. 

Burdock  leaves,  13. 

Bush  &  Son  &  Meissner,  quoted,  94. 

Cabbage,  aphis,  267  ;  bug,  harlequin,  269 ; 
butterfly,  268;  club-foot,  266;  root, 
266;  enemies  and  diseases,  266-270; 
finger-and-toe,  266 ;  fly,  13 ;  harlequin 
bug,  269  ;  plusia,  267 ;  root-maggot, 
268 ;  treatment  of,  135 ;  worm,  263. 


Cceoma  luminatum,  356. 

Calcium  chloride  and  alum,  44. 

California  spider,  321. 

Calla  nozzle,  202. 

Canada,  spraying  in,  112-114. 

Cane  borer,  raspberry,  357 ;  rust,  rasp- 
berry, 355. 

Canker,  4 ;  worm,  8  ;  and  London  purple, 
67 ;  apple,  249, 251 ;  cherry,  275 ;  early 
treatment  of,  63 ;  elm,  291 ;  experi- 
ments on,  79  ;  Paris  green,  first  use 
for,  62  ;  plum,  249,  343. 

Cantharides,  4. 

Capol,  de,  quoted,  44. 

Carbolic  acid,  18,  133;  and  glycerine, 
134  ;  soap,  134 ;  emulsion,  134 ;  tested, 
57. 

Carbolized  plaster,  134. 

Carbon  bisulphide,  52,  134;  and  kero- 
sene, 135;  emulsion  (Italian),  145. 

Carbonate  of  ammonia  and  copper  car- 
bonate, 141 ;  copper,  137 ;  soda,  52. 

Carnation,  anthracnose,  271 ;  blight,  273 ; 
diseases,  271, 272;  rust,  272;  spot,  273. 

Carpet-bug  destroyer,  analysis  of,  118. 

Carpocapsa  pomonella,  252-255. 

Carrere  powder,  41. 

Case-worm,  apple,  251,  252. 

Cassida?,  369. 

Catalpa,  leaf  spot,  273  ;  treatment,  102. 

Caterpillar,  of  insects,  228. 

Caterpillars,  destruction  of,  51. 

Cauliflower,  enemies  and  diseases,  273 ; 
see  also  Cabbage. 

Cavazza's  Bordeaux  mixture,  131. 

Cedar-apple,  242. 

Celery,  blight,  274 ;  caterpillar,  274,  324 ; 
enemies  and  diseases,  274 ;  leaf  blight, 
274 ;  rust,  274 ;  sun-scald,  274. 

Ceratocystis  fimbriata,  368. 

Cercospora  angulata,  285;  Apii,  274; 
beticola,  264;  circumcissa,  239;  Re- 
sedce,  314;  roscecola,  358;  Fi0&»,372. 

Chafer,  rose,  362. 

Chapin,  quoted,  62. 

Chapin's  apple  leaf  sewer,  64. 

Charbon,  grape,  297-300. 

Chemicals,  early  use  of,  19. 

Cherry  black  knot,  111,  275;  brown  rot, 
274 ;  canker-worm,  275  ;  curculio,  275 ; 
enemies  and  diseases,  274,  275 ;  leaf 
blight,  275;  powdery  mildew,  275; 
slug,  275. 


388 


The  Spraying  of  Plants. 


Chester,  F.  D.,  mentioned,  128 ;  on  grape 

diseases,  10T ;  pear  diseases,  109,  110 ; 

quoted,  137,  140,  141. 
Chloride  of  calcium  and  alum,  44 ;  copper, 

141 ;  iron,  101,   151 ;   mercury  wash, 

160;  sodium,  169. 
Chlorophyll,  229. 
Chrysalis,  228. 
Chrysanthemum,  disease,  275,  276;  leaf 

spot,  275  ;  new  leaf  spot,  276. 
Chrysobothrisfemorata,  248. 
Cigar-case-bearer,  apple,  251,  252 ;  pear, 

251,  835. 
Cladosporium  carpophilum,  327 ;  den- 

driticum,   experiments  on,  22;  ful- 

imm,  370  ;  sp.  820. 
Clay,  8,  9. 

Climax  nozzle,  201 ;  potato  sprayer,  194. 
Cline,  G.  W.,  mentioned,  112. 
Olisiocampa  Americana :•,  77,  258. 
Clock  pumps,  217. 
Cloque,  47. 

Club-foot,  cabbage,  266. 
Coal  oil,  152 ;  tar,  136. 
Cobbett,  W.,  quoted,  10. 
Coccotorus  scutellaris,  344. 
Coccus,  7. 

Cochylis  roserana,  destruction  of,  52. 
Codlin-moth  and  London  purple,  63,  68  ; 

Paris  green,  64 ;  apple,  252,  255 ;  first 

treated  by  experimentation,  65;  with 

Paris  green,  63 ;  pear,  252,  335. 
Cold  water,  179. 

Coleophora  Fletcher ella,  251,  252. 
Coleosporium  Sonchi-arvensis,  260. 
Colletotrichwn  Spinacem,  363. 
Colorado  potato  beetle,  351. 
Colsa  oil,  52. 
Combination  of  arsenites  and  kerosene 

emulsion,  155. 
Combinations,  148 ;  of  insecticides  and 

fungicides,    186;   of  insecticides   and 

fungicides,  suggested,  105. 
Combined  cistern  and  force-pump,  191 ; 
Composition  of  Forsyth,  6. 
Oonotrachelus  nenuphar,  275,  343. 
Cook,  A.  J.,  mentioned,  67,  68 ;  on  kero- 
sene emulsion,  81 ;  quoted,  62,  63,  64, 

184,  283,  235,  251. 
Cook's  hard  soap  emulsion,   154 :   soft 

soap  emulsion,  154. 
Copper,  absorbed  by  foliage,  234,  235; 

acetate,  137  ;  aceto  arsenite,  121 ;  action 


on  foliage,  234  ;  plants,  235 ;  soil,  286; 
amount  in  soil,  236;  carbonate,  137; 
ammoniacal  solution,  138 ;  and  ammo- 
nium carbonate,  141 ;  dextrine,  44 ; 
chemistry  of,  137 ;  early  use  upon 
grapes,  27 ;  in  ammonia,  introduction 
into  America,  101 ;  precipitated,  sug- 
gested, 36;  recommended,  46;  chlo- 
ride, 141 ;  compounds  and  sugar,  173 ; 
hydrate  and  ammonia,  36;  sulphur, 
44  ;  perforation  of,  44 ;  recommended, 
46  ;  hydro  carbonate,  44  ;  in  food,  235 ; 
mixture  of  Gironde,  125;  nitrate,  in 
soil,  287 ;  phosphate,  44 ;  early  use 
upon  grapes,  27 ;  soda  mixture,  see 
copper  carbonate,  141 ;  sodium  hypo- 
sulphite, 141 ;  sulphate,  action  on 
foliage,  46;  spores,  22,  235;  ammo- 
niated,  117 ;  and  ammonium  carbon- 
ate, 151 ;  sulphate,  85 ;  carbonate  of 
soda,  36;  lime  mixture,  125;  Paris 
green,  105;  sodium  carbonate,  44; 
sulphuric  acid,  143  ;  wheat  smut,  318  ; 
anhydrous,  143 ;  as  a  fungicide,  142 ; 
dissolved  in  ammonia,  30 ;  early  use 
of,  17,  22,  27 ;  in  Australia,  57 ;  Eng- 
land, 55;  soil,  237;  on  foliage,  34; 
preparation  of,  142 ;  salt  and  lime 
wash,  162  ;  test  for  purity,  142 ;  tested, 
41;  value  of,  on  posts,  etc.,  24;  sul- 
phide, early  use  upon  grapes,  27; 
sulphocyanide,  44 ;  sulphosaccharate, 
42,  173. 

Copperas,  151,  see  also  Iron  sulphate. 

Coquillett,  D.  W.,  work  of,  85,  87. 

Corn,  affected  by  copper  salts,  235,  237 ; 
enemies  and  diseases,  276,  277  ;  insect 
enemies,  277 ;  root-worm,  southern, 
283 ;  smut,  276. 

Cornell  mixture,  143. 

Corrosive  sublimate,  9  ;  use  of,  160. 

Cotton  blight,  10  ;  caterpillar,  277 ;  ene- 
mies and  diseases,  277, 278  ;  leaf-worm, 
277 ;  worm,  277,  286;  Paris  green  for, 
61. 

Cottonwood,  leaf-beetle,  278  ;  rust,  278. 

Craig,  quoted,  112,  114. 

Cranberry,  blackhead,  280  ;  enemies  and 
diseases,  279-281  ;  fire-worm,  280 ; 
fruit-worm,  280  ;  gall  fungus,  279  ;  red 
rust,  279  ;  rot,  279 ;  scald,  279  ;  vine- 
worm,  280  ;  worm,  280. 

Craw,  quoted,  149-151. 


Index. 


389 


Crawford,  F.  S.,  quoted,  57. 

Creed,  W.,  mentioned,  69. 

Crioceris  Atparagi,  260. 

Cruickshank,  G.,  quoted,  80. 

Cuboni,  C.,  quoted,  20,  157. 

Cucumber,  enemies  and  diseases,  281- 
284  ;  melon-louse,  283 ;  worm,  2S3  ; 
mildew,  281,  314;  powdery  mildew, 
283;  southern  corn  root-worm,  283; 
spotted  beetle,  283 ;  striped  beetle,  284. 

Cupram,  138. 

Cupric-steatite,  174. 

Cuprophosphate,  44. 

Cuprosteatite,  44, 144. 

Curculio,  apple,  255,  256  ;  spraying  for, 
69 ;  on  apricot,  260  ;  cherry,  275 ;  pear, 
255,  335 ;  plum,  332,  343  ;  spraying  for, 
68-74 ;  peach,  329. 

Currant,  anthracnose,  285;  borer,  286; 
bug,  yellow-lined,  287 ;  enemies  and 
diseases,  2S5-290;  green,  leaf-hopper, 
289 ;  imported  borer,  286 ;  leaf  blight, 
285 ;  spot,  285 ;  rust.  2S5  ;  sawfly,  286 ; 
worm,  13 ;  imported,  286 ;  introduction 
into  America,  59. 

Cyanide  of  potassium,  149. 

Cyclone,  Bean's,  nozzle,  204 ;  nozzle, 
"202,203. 

CylindrospoHum  Padi,  275,  339. 

Cystopus  IpomtKce-pandurance,  368. 

Dactylopius  adonidum,  309. 
Dahlia,  insects  affecting,  290. 
Dakruma  con  colutella,  293. 
Dalmatian  insect  powder,  163. 
Davenport's  modification  of  sulphatine, 

57. 

David  powder,  33, 144;  in  Australia,  57. 
Deane,  S.,  quoted,  4,  6. 
Death  to  rose-bugs,  analysis  of,  118. 
Deming  MT g  Co.,  mentioned,  195,  197. 
Dendrolene,  250. 

Dfpressa  heracliana,  325.          » 
Devices,  spraying,  207-224. 
Dextrine  and  copper  carbonate,  44. 
Diabrotica,   12 ;  punctota,  283 ;    «?*Y- 

tata,  284. 

Diffuser,  nozzle,  201. 
Diploninpyritora,  335. 
Diseases  treated  in  America  in  1887, 102  ; 

in  1888, 103  ;  in  18S9, 104-106 ;  in  1890, 

106-108 ;  in  1891, 10>-110,  in  1892,  110  ; 

in  1894,  111. 


Disulphide  of  carbon,  184. 
Doryphora  10-lineata,  351. 
Dosch,  H.  E.,  quoted,  162. 
Douglas,  W.  &  B.,  mentioned,  190. 
Downy  mildew,  grape,  see  also  Grape, 

300-302  ;  appearance  in  France,  19,  25 ; 

potato,  347. 
Dung,  4,  6,  16. 
Dust  sprayer,  Sirocco,  205. 

Early  blight,  potato,  345. 

Eau'celeste,  action  on  foliage,  46 ;  chem- 
istry of,  145 ;  in  Australia,  57 ;  modi- 
fied, 160;  preparation  of,  144;  sug- 
gested, 30 ;  tested,  35,  38,  41. 

Eau  Grison,  16,  147,  307. 

Eclair,  knapsack  pump,  187. 

Eddy-chamber  nozzles,  203,  210;  the 
spray  of,  224. 

Eggplant,  anthracnose,  290;  leaf  spot, 
290. 

Elder,  7, 11,  13. 

Elm,  canker-worm,  291  ;  flea-beetle,  292 ; 
gipsy  moth,  291 ;  insects  affecting,  291, 
292 ;  leaf-beetle,  292  ;  span-worm,  291 ; 
trees,  spraying  with  steam  power, 
195. 

Emerald  green,  121. 

Emphytu*  maculatv*,  366. 

Empoa  albopicta,  289. 

Emulsions,  kerosene,  and  Bordeaux  mix- 
ture, 156 ;  milk,  153  ;  pyrethrum,  156 ; 
soaps,  154,  155;  linseed"  oil,  158;  prep- 
aration of,  145. 

Engines,  garden,  11 ;  gas,  196 ;  steam, 
195,  196. 

England,  fungicides  in.  55;  insecticides 
in,  56 ;  spraying  in,  54. 

English  purple  poison,  74 ;  composition, 
123 ;  use  of,  123. 

Entomosporium  maculatum,  333, 
353. 

Erytiphe  Cichoracearum,  281,  872 ; 
Jfartii,  326. 

Erythrontura  Vitis,  306. 

Eudioptis  hyalinata,  283. 

Eureka  nozzle,  199. 

Europe,  spraying  in,  53. 

European  hellebore,  148. 

Exoaacu*,  47 ;  deformans,  329 ;  Prwnt, 
34-2. 

Experiment  stations,  establishment  of, 
102. 


390 


The  Spraying  of  Plants. 


Fairchild,  D.  G.,  quoted,  234. 

Fall  web-worm,  apple,  256. 

Fantail  nozzle,  199. 

Farmyard  drainage,  12. 

Fernald,  C.  H.,  quoted,  77,  248. 

Ferrocyanide  of  potassium  and  Bordeaux 
mixture,  128,  129 ;  chemical  action  of, 
146  ;  recommended,  46  ;  test  for  iron, 
151 ;  use  of,  129. 

Ferrous  chloride,  151 ;  sulphate,  tested, 
57. 

Fessenden,  T.,  quoted,  10, 11. 

Fichet's  insecticide,  50. 

Field  Force  Pump  Co.,  mentioned,  191. 

Finger-and-toe,  of  cabbage,  266. 

Fir  balsam  and  kerosene  emulsion,  156. 

Fire  blight,  pear,  334. 

Fire,  for  strawberry  leaf  blight,  865. 

Fire-worm,  cranberry,  280. 

Fish-oil,  8 ;  and  soap,  171 ;  soap,  146 ; 
use  of,  166-169. 

Flax  rubbish,  8. 

Flea-beetle,  345 ;  elm,  292 ;  grapevine, 
306  ;  on  potato,  351. 

Fletcher,  J.,  mentioned,  114. 

Florida  spray  pump,  191. 

Flour,  146. 

Flowers  of  sulphur,  uses  of,  175. 

Foex,  M.  G.,  mentioned,  96. 

Foliage,  copper  absorbed  by,  234. 

Foliage-eating  insects,  309. 

Formulas  and  materials,  115-180. 

Forsyth,  W.,  quoted,  6,  7. 

Forsyth's  composition,  6. 

Fostite ;  see  Sulphosteatite. 

Four-lined  leaf  bug,  287,  373  ;  plant  bug, 
287,  290. 

French  applications  of  fungicides  to 
grapes,  49 ;  fungicides,  introduction 
of,  93,  95,  99 ;  green,  121 ;  knapsack 
pumps  in  America,  186. 

Frenching,  329. 

Fruit,  keeping  qualities  of  sprayed,  238 ; 
not  poisoned  by  arsenites,  231  ;  rot,  of 
peach,  328;  spot,  pear,  333;  spot, 
quince,  353 ;  worm,  cranberry,  280 ; 
gooseberry,  293. 

Fuma,  134. 

Fungi,  classes  of,  229  ;  definition  of,  228, 
229 ;  methods  of  destroying,  230 ;  treat- 
ment of,  230. 

Fungicides,  action  on  soil,  235-237 ;  and 
insecticides,  action  of,  225-238;  com- 


parative test  of,  48 ;  early  trials  of,  19  ; 
first  used  in  America,  87  ;  French,  in- 
troduction of,  93 ;  test  by  Bencker,  44 ; 
of  adhesive  powers,  47  ;  in  America,  93, 
107,  108,  114  ;  use  in  America,  92-114. 

Fungivore,  21. 

Fusicladium  dendriticum,  243-247; 
Pyrinum,  early  treatment  of,  47  ;  ex 
periments  on,  22. 

Gaillot's  knapsack  pump,  186. 

Galeruca  xanthm/ielcena,  292. 

Gall  fungus,  cranberry,  279. 

Galloway,  B.  T.,  quoted,  107, 108 ;  knap- 
sack pump,  188,  189. 

Garden  engine,  11,  184,  185 ;  early  form 
of,  190. 

Garman.  H.,  quoted,  241. 

Gas  engines,  196 ;  treatment,  see  Hydro- 
cyanic acid  gas. 

Gases  for  grape  mildew,  96. 

Gayon,  U.,  quoted,  48. 

Gem  nozzle,  199. 

Germany,  spraying  in,  54. 

Gillette,  C.  P.,  and  plum  curculio,  71 ; 
quoted,  105,  106. 

Gipsy  moth,  on  elm,  291. 

Girard,  A.,  quoted,  47. 

GlcKosporiurn  fructigenum,  240,  305; 
melongenea,  290  ;  necator,  355 ;  ner- 
visequum,  369  ;  Ribis,  285. 

Glover's  scale,  322. 

Glucose,  174. 

Glue  and  arsenites,  147 ;  and  Bordeaux 
mixture,  48 ;  value  of,  147. 

Glycerine  and  carbolic  acid,  134 ;  Grison 
liquid,  97  ;  phenic  acid,  24. 

Goeze,  J.  A.  E.,  quoted,  5. 

Goff,  E.  8.,  mentioned,  65,  196;  quoted, 
88. 

Golden  bugs  on  sweet  potato,  369. 

Gooseberry  enemies  and  diseases,  292- 
294;  fruit-worm,  293;  mildew,  treat- 
ment, 102,  292  ;  sawtiy,  13,  286. 

Gophers,  treatment  of,  135. 

Gordon,  G.,  quoted,  57. 

Gouger,  plum,  344. 

Gourd,  bitter,  5. 

Graduating  spray  nozzles,  198,  199. 

Grain,  rusts,  319 ;  treatment  of,  106, 
135. 

Grape,  anthracnose,  294 ;  treatment,  23, 
37,  45,  295;  bird's-eye  rot,  294-296; 


Index. 


391 


bitter  rot,  305 ;  black  rot,  297-300 ; 
early  treatment  of,  89 ;  first  controlled 
by  Bordeaux  mixture,  40;  fungicides 
for,  39,  41  ;  in  France,  39  ;  brown  rot, 
300-302 ;  charbon,  297-300  ;  cleaning, 
105;  diseases,  early  treatment  of,  in 
America,  94,  95,  99,  100 ;  treatment  of, 
107;  downy  mildew,  300-302;  early 
treatment  with  fungicides  in  America, 
93 ;  introduction  into  Europe,  53 ; 
methods  of  treatment,  45 ;  treatment 
with  iron  sulphate,  21 ;  lime,  20,  27 ; 
sulphur,  21 ;  enemies  and  diseases, 
294-306;  flea-beetle,  306;  gray  rot, 
300-302;  leaf-hopper,  306;  powdery 
mildew,  303,  304;  rattles,  304;  ripe 
rot,  305 ;  sawfly,  305 ;  scab,  294 ;  shell- 
ing, 304 ;  slug,  305  ;  steely-bug,  306 ; 
thrip,  306  ;  vine  flea-beetle,  306. 

Grapes,  and  Bordeaux  mixture,  232,  233  ; 
injured  by  Bordeaux  mixture,  232,  233 ; 
sprayed,  analysis  of,  232,  233  ;  value  of 
treatments,  237. 

Graptodera  ehalybea,  306. 

Gravity  machines,  194. 

Gray,  F.  M.,  mentioned,  186. 

Gray  rot,  grape,  300-302. 

Green,  W.  J.,  quoted,  73,  74. 

Green-fly,  308 ;  leaf-hopper,  currant,  289  ; 
-striped  maple-worm,  312 ;  vitriol,  151. 

Greenhouse,  pests,  307-311 ;  remedies 
used  in,  307-311. 

Grison  liquid,  16 ;  preparation  of,  147. 

Grub  of  insects,  228. 

Gunnis,  W.  R.,  quoted,  196. 

Guns,  powder,  204,  205. 

Gymnonporangium,  macropus,  242. 

Gyp  sine,  120. 

Haggerston,  P.,  mentioned,  14. 
Halsted,   B.    D.,   mentioned,  106,  133; 

publications  of,  106 ;  quoted,  242,  264, 

267,  363. 

Haltica  fttriolata,  351. 
Hamilton's  recipe,  15. 
Handles,  pump,  210. 
Hard  soap  and  kerosene,  154. 
Harlequin  cabbage-bug,  269. 
Harris,  J.,  quoted,  13. 
Hartshorn,  116. 
Hatch  bill,  mentioned,  64. 
Haynes,  E.  P.,  mentioned,  62. 
Heath  broom,  181. 


Hellebore,  5,  13,  15, 18 ;  analysis  of,  118 ; 

properties  of,  148 ;  uses  of,  148. 
Hemery  compound,  15. 
Hemingway  &  Co.,  letter  of,  65,  66. 
High,  G.  M.,  quoted,  93. 
Hilgard,  E.  W.,  quoted,  180. 
History,    early,    of  liquid    applications, 

1-18;  evolution    of  nozzles,  197-204; 

pumps  and  syringes,  181-197. 
Hollyhock-bug,  312 ;  rust,  311. 
Horizontal-acting  pumps,  214,  216. 
Horse-power  sprayer,  first  form  adver- 
tised, 193. 
Hot  water,  178,  see  also  Water ;  and  smut 

of  grains,  315-319. 
Howard,  L.  O.,  quoted,  69. 
Hoyt,  8.,  quoted,  195,  196. 
Hubbard,  H.  G.,  on  kerosene  emulsion, 

82 ;  quoted,  82,  83. 

Hubbard-Riley  kerosene  emulsion,  155. 
Hydrate  of  copper  and  sulphur,  44. 
Hydrocarbonate  of  copper,  36,  44. 
Hydrocyanic  acid  gas,  amounts  to  use, 

149 ;  preparation  of,  148. 
Hyphae,  229. 

Hyphantria  cunea,  256. 
Hyposulphite  of  soda,  172  ;  first  use  ot, 

88. 
Hyssop,  5. 

Imago  of  insects,  228. 

Imported  cabbage  butterfly,  268;  cur- 
rant borer,  286 ;  worm,  286 ;  elm-leaf- 
beetle,  64. 

Injector  for  bisulphide  of  carbon,  135. 

Insect  powder,  163. 

Insects,  chewing,  228;  foliage-eating, 
309  ;  methods  of  destroying,  227,  228 ; 
sucking,  228 ;  transformation  of,  228. 

Insecticides,  action  upon  soil,  235,  236 ; 
and  fungicides,  action  of,  225,  238 ;  in 
England,  56 ;  France,  50 ;  patent,  162. 

Iron,  chloride,  101 ;  use  of,  151 ;  salts, 
early  use  upon  grapes,  27 ;  sulphate, 
45 ;  action  upon  spores,  235 ;  and  grape 
anthracnose,  23 ;  sulphuric  acid,  169, 
170 ;  as  an  insecticide,  90 ;  early  use 
of,  21,  22;  properties  of,  151; 'testa 
for,  151  ;  uses  of,  151. 

Italy,  spraying  in,  53. 

Jager,  G.  V.,  quoted,  119. 
Japy,  knapsack  pump,  187,  188. 


392 


The  Spraying  of  Plants. 


Jensen,  J.  L.,  hot  water  treatment  of 
smut,  315-319  ;  quoted,  315,  319. 

Johnson,  S.  W.,  mentioned,  110. 

Johnson's  mixture,  140,  152. 

Johnston's  engine,  183. 

Jones,  L.  E.,  mentioned,  133  ;  on  potato 
diseases,  108. 

Joosten,  C.  H.,  mentioned,  174. 

Judd,  Joseph,  quoted,  381. 

Juniper  web-worm,  64. 

Kainit,  163. 

Katterbach's  knapsack  pump,  186. 

Kedzie,  K.  C.,  mentioned,  233. 

Keeping  qualities  of  sprayed  fruit,  238. 

Kellerman,  W.  A.,  mentioned,  106. 

Kenrick,  W.,  quoted,  12. 

Kerosene,  18;  and  black  knot,  106; 
Bordeaux  mixture,  136  ;  carbon  bisul- 
phide, 135 ;  condensed  milk,  153 ;  milk 
emulsion,  82,  153  ;  soap  emulsion,  81, 
154 ;  water,  device  for  mixing,  196 ; 
applied  in  water,  79  ;  early  use  of,  79. 

Kerosene  emulsion  and  arsenites,  155 ; 
balsam  of  fir,  156 ;  Bordeaux  mixture, 
156 ;  resin  washes,  136 ;  sulphide  of 
potash,  180 ;  applied  with  gas  engine, 
196;  Hubbard-Riley  formula,  84;  in 
France,  51 ;  introduction  of,  80,  84 ; 
Italian,  145 ;  in  England,  66 ;  proper- 
ties of,  152  ;  Pyrethrum  emulsion,  156 ; 
when  first  emulsified,  80,  81. 

Kilgore,  B.  W.,  quoted,  76,  119. 

Knapsack  pump,  Albrand,  187,  188 ; 
Eclair,  187:  Galliot's,  186;  Galloway, 
188,  189 ;  Japy,  187, 188 ;  Katterbach's, 
186 ;  Vigouroux,  187,  188 ;  with  kero- 
sene attachment,  197 ;  pumps,  intro- 
duction into  America,  186 ;  uses  of, 
208 ;  sprinkler,  early  forms,  186 ;  with 
air-pump,  188,  189. 

Koebele,  A.,  work  of,  85,  86. 

Lcestadia  Bidwellii,  297-300. 

Lafitte,  P.  de,  quoted,  23,  29. 

Lampblack,  12. 

Larva,  of  insects,  228. 

Laure,  J.,  powder  of,  21. 

Laws,  spraying,  375-381 ;  Australia,  58  ; 
California,  375;  Canada,  376;  Oregon, 
379;  Massachusetts,  377;  Michigan, 
877  ;  Tasmania,  58 ;  Utah,  880. 

Laws,  spraying,  unconstitutional,  381. 


Lead  arsenate,  120 ;  see  also  Arsenate  of 
lead. 

Leaf-beetle,  cotton  wood,  278 ;  imported, 
elm,  292  ;  blight,  almond,  239  ;  celery, 
274  ;  cherry,  275 ;  currant,  285 ;  mign- 
onette, 314;  pear,  333;  plum.  339; 
quince,  353  ;  rose,  358  ;  strawberry, 
364 ;  sycamore,  369 ;  blister,  pear,  336 ; 
bug,  four-lined,  287 ;  curl,  peach,  329  ; 
hopper,  grape,  306;  green,  currant, 
289;  rose,  363;  mite,  orange,  321; 
mould,  sweet  potato,  368 ;  notcher, 
orange,  321 ;  roller,  strawberry,  366  ; 
rust,  apricot,  260 ;  aster,  260 ;  balm  of 
Gilead,  261 ;  cottonwood,  278 ;  peach, 
331 ;  skeletonizer,  apple,  257 ;  spot, 
beet,  264 ;  catalpa,  273 ;  chrysanthe- 
mum, 275;  currant,  285;  eggplant, 
290 ;  maple,  312 ;  orange,  321 ;  quince, 
353 ;  rose,  358 ;  sweet  potato,  368 ; 
worm,  cotton,  277. 

Leather  in  pumps,  208  ;  scraps,  8. 

Lecanium,  344 ;  Olece,  treatment  of,  150. 

Leek,  5. 

Leizour,  quoted,  51. 

Lesne,  A.,  quoted,  52. 

Lettuce-worm,  green,  290. 

Lewis  nozzle,  201. 

Lichens,  314. 

Lilly  nozzle,  202. 

Lima  bean,  264. 

Lime,  6,  7,  8,  11 ;  action  on  copper  salts, 
in  soil,  237  ;  foliage,  156,  234 ;  spores, 
235  ;  and  arsenites,  76, 105 ;  soap  wash, 
171 ;  sulphur,  chemistry  of,  158 ;  mix- 
ture, 147 ;  powder,  176 ;  chemistry  of, 
156  ;  first  use  of,  for  downy  mildew  of 
grape,  20 ;  for  plant-lice,  5 ;  salt,  sul- 
phur wash,  157 ;  and  copper  sulphate 
wash,  162  ;  sulphide,  16 ;  preparation 
of,  158 ;  uses  of,  157 ;  wash  for  curcu- 
lio,  16. 

Lina  scripta,  278. 

Lindley,  Geo.,  quoted,  11. 

Linseed  oil  emulsion,  158. 

Lintner,  J.  A.,  quoted,  251. 

Liquid  applications,  early  history  of,  1. 

Liquids  and  powders  compared,  205-207 ; 
application  of,  205-207. 

Litmus  paper,  use  of,  46. 

Little  Climax,  191 ;  Giant  pump,  191. 

Liver  of  sulphur;  see  Potassium  sul- 
phide. 


Index. 


393 


Lodeman,  E.  G.,  mentioned,  133;  on 
black-knot,  112. 

London  purple,  analyses,  124 ;  and  Bor- 
deaux mixture,  105;  canker-worms, 
67 ;  codlin-moth,  63,  68 ;  introduction 
of,  65-67 ;  report  of  first  trials,  66 ;  use 
of,  124. 

Long  scale,  322. 

Loose  smut,  oats,  315-319 ;  wheat,  315- 
319,  373. 

Loudon,  J.  C.,  quoted,  11,  14, 

Lowell  nozzle,  199. 

Lye,  9,  11;  and  sulphur,  159;  whale-oil 
soap,  159 ;  uses  of,  159. 

Lygus  pratensis,  366. 

Macdougal's  syringe,  183. 

Machine  for  mixing  kerosene  and  water, 

196,  197. 
Machinery,  care  of,  224 ;  spraying,  207- 

224  ;  early  forms  of,  185. 
Macrodactylus  wibspinosus,  362. 
Macrosporium  Solani,  345 ;   Tomato, 

370. 

Maggot,  apple,  257 ;  onion,  320. 
Manufacture  of  spray  pumps  increasing, 

191. 
Maple,  enemies  and  diseases,  312,  313; 

green-striped  maple-worm,  312 ;    leaf 

spot,  312  :  tussock  moths,  313. 
Jfargarodes  quadristigmalis,  352. 
Marseilles  nozzle,  204. 
Masson  nozzle,  199. 
Materials  for  spraying,  115-180. 
Maynard,  S.  T.,  quoted,  111,  158. 
McGowen,    J.    J.,    automatic    cleaning 

nozzle,  200,  201,  210 ;  mentioned,  200 ; 

nozzle,  202. 

McMichael,  J.  K.,  quoted,  112. 
McMurtrie,  A.,  quoted,  120. 
Mealy  bug,  362  ;  treatment  of,  309  ;  wing, 

orange,  321. 
Mearns,  J.,  quoted,  12. 
Measures,  metric  system,  382,  383 
Jfflampsora  Populina,  278. 
Melon-louse  on  cucumber,  283 ;  worm, 

on  cucumber,  283. 
Mercuric  chloride,  160  ;  wash,  160. 
Mercury,  red  oxide  of,  52. 
Merritt,  Justice,  381. 
Methods  of  destroying  insects,  227,  228 ; 

spraying,  226. 
Metric  system,  382,  383. 


Midge,  pear,  335. 

Mignonette,  disease,  314  ;  leaf  blight,  314. 

Milco,  G.  N.,  mentioned,  79. 

Mildew,  cucumber,  281,  314;  downy, 
grape,  300-302;  potato,  347;  goose- 
berry, 292;  onion,  319;  pansy,  324; 
pea,  326  ;  peach,  10,  331  ;  treatment 
of,  15,  381  ;  powdery,  cucumber,  283  ; 
grape,  808,  304;  muskmelon,  314  ;  plum, 
241,  343  ;  pumpkin,  314,  352  ;  squash, 
814,  864;  watermelon,  281,  373;  rose, 
17,  359  ;  spinach,  363  ;  strawberry,  365  ; 
yerbena,  281,  372  ;  violet,  324,  372. 

Mildews,  early  treatment  of,  12. 

Milk,  condensed,  and  kerosene,  153. 

Millardet,  A.,  quoted,  22,  27,  37,  48. 

Millardet's  mixture,  125. 

Mite,  309  ;  orange,  321. 

Mitis  green,  121. 

Mixture  No.  5,  160  ;  introduction  of, 
107. 

Modified  eau  celeste,  160  ;  suggested,  37. 

Molasses  and  Bordeaux  mixture,  43; 
chemistry  of,  173  ;  uses  of,  173. 

Mold,  leaf,  "of  sweet  potato,  368;  white, 
of  sweet  potato,  368. 

Monarch  potato  sprayer,  195. 

Moniliafructigena,  274. 

Monroe,  W.  R.,  mentioned,  205. 

Morrill  &  Morley,  mentioned,  192. 

Mortar,  8. 

Mosquitos,  treatment  of,  153. 

Mosses,  314. 

Moulton,  F.  C.,  mentioned,  77. 

Murgantia  histrionica,  269. 

Murray,  J.,  quoted,  13. 

Muskmelon,  powdery  mildew,  314. 

Mycelium,  229. 

Myers  nozzle,  204. 

Mytilaspis  Gloverii,  322;  pomorum, 
258. 

Neal,  quoted,  83. 
Neal's  mixture,  83. 


,  286. 
New  Bean  nozzle,  199  ;  leaf  spot,  chrys- 

anthemum, 276. 
Nicol's  recipe,  14. 
Nicotiana  Tabacum,  176. 
Nitre,  14. 

Nitro-benzina,  emulsion,  145. 
Nixon  Nozzle  and  Machine  Co.,  founded, 

191  ;  mentioned,  191,  193,  201. 


394 


The  Spraying  of  Plants. 


Non-poisonous  potato-bug  destroyer, 
analysis  of,  118. 

Normal  Bordeaux  mixture,  108,  130. 

Nova  Scotia,  spraying  in,  113. 

Nozzle,  Acme,  204 ;  automatic  cleaning, 
200  ;  Bailey,  200  ;  Ball,  202  ;  Barnard, 
203;  Bean's  Cyclone,  204;  Bordeaux, 
199, 210  ;  Boss,  199  ;  Calla,  202 ;  Climax, 
201 ;  Diffuser,  201 ;  Eureka,  199  ;  Fan- 
tail,  199  ;  Gem,  199  ;  Ideal,  222 ;  Lewis, 
201;  Lilly,  202;  Lowell,  199;  Mar- 
seilles, 204 ;  Masson,  199 ;  McGowen, 
200,  202  ;  Myers,  204 ;  New  Bean,  199  ; 
Peerless,  199;  Kiley,  203,  204;  Ver- 
morel,  204 ;  with  lance,  204 ;  Vigour- 
oux,  201 ;  Wellhouse,  200,  210. 

Nozzles,  cyclone,  202,  203 ;  eddy  chamber, 
202,  203,  210;  graduating  spray,  198, 
199  ;  history  of,  197-204  ;  principles  of 
construction,  198 ;  sprays  produced  by, 
222,  224. 

Nursery  stock,  treatment  of,  104,  111. 

Nux  vomica,  15. 

Oat  loose  smut,  315-319  ;  plants  affected 
by  copper  salts,  237 ;  rust,  319 ;  smut 
and  potassium  sulphide,  318. 

Obera  bimaculata,  357. 

Ocneria  dispar,  291. 

Oidium  eryttiphoides,  372;  Tuckeri, 
53. 

Oil  and  alkali  wash,  161 ;  fish,  use  of,  166- 
169 ;  petroleum,  5 ;  train,  7, 9  ;  whale,  7. 

Oils,  5,  52,  161. 

Oleo-sulphide  of  carbon,  52. 

Oliver,  P.,  quoted,  21. 

Onion,  enemies  and  diseases,  319,  320 ; 
maggot,  320 ;  mildew,  319 ;  rust,  319  ; 
smut,  319. 

Oospora  scabies,  265,  350. 

Orange,  California  spider,  321 ;  enemies 
and  diseases,  320-324;  Glover's  scale, 
322;  leaf  mite,  321 ;  notcher,321;  scab, 
treatment,  97 ;  spot,  321 ;  long  scale, 
322  ;  mealy-wing,  321  ;  mite,  821  ; 
oyster-shell  scale,  322  ;  red  spider,  321 ; 
spotted  mite,  321  ;  rust-mite,  822 ; 
raspberry,  355 ;  San  Jose  scale,  323 ; 
scab,  320 ;  spider,  821 ;  trees,  treat- 
ment of,  150. 

Orchards,  old,  spraying  of,  218-220  ; 
sprayed  and  stock,  233,  234. 

Oregon  wash,  162. 


Orgyia,  sp.,  313. 

Oriental    fertilizer   and    bug   destroyer, 

analysis  of,  118. 

Origin  of  Bordeaux  mixture,  24. 
Orthotylua  delicatus,  312. 
Osborn,  II.,  and  plum  curculio,  70. 
Otto,  K.,  quoted,  235. 
Oxalic  acid,  50. 
Oyster-shell  bark -louse,   on  apple,  258; 

scale,  322. 

Pcecilocapsus  lineatus,  287. 

Paleacrita  vernata,  275. 

Pansy,  mildew,  324 ;  rust,  324. 

Papilio  Asterias,  324. 

Paraffine,  56,  162. 

Parasitic  fungi,  229,  230. 

Paris  green,  action  on  foliage,  122 ;  soil, 
236;  analysis  of,  118;  and  ammoniacal 
copper  carbonate,  106;  copper  sul- 
phate, 105 ;  glue,  147 ;  lime,  122 ;  as  a 
fungicide,  98,  122;  composition,  120; 
early  methods  of  application,  61 ;  first 
use  for  canker-worm,  62  ;  codlin-moth, 
62 ;  for  cotton-worm,  61 ;  plum  curcu- 
lio, 69-74;  potato  beetle,  60,  185; 
kerosene,  and  Bordeaux  mixture,  136 ; 
law  for  spraying  with,  376 ;  manner  of 
use,  123 ;  patent  preparations  of,  60 ; 
properties,  120;  upon  fruit,  231. 

Paris  purple,  74 ;  composition,  125 ;  use 
of,  125. 

Parkinson,  John,  quoted,  4. 

Parsley-worm,  324,  325. 

Parsnip,  web- worm,  325. 

Pasturing  stock  in  sprayed  orchards,  233, 
234. 

Patent  insecticides,  60,  61,  162. 

Patrigeon,  G.,  quoted,  36,  45,  46. 

Pea-bug,  326;  mildew,  325;  rust,  326; 
weevil,  326. 

Peas,  affected  by  copper  salts,  235. 

Peach,  black  aphis,  332  ;  spot,  327  ;  borers, 
332  ;  brown  rot,  328 ;  curl,  treatment, 
47,  329;  enemies  and  diseases,  327- 
832 ;  Trenching,  329  ;  fruit  rot,  328 ; 
leaf  curl,  329  ;  rust,  331 ;  mildew,  treat- 
ment, 10,  15,  332 ;  rosette,  332 ;  twig 
blight,  328 ;  yellows,  332. 

Pear  blight,  experiments  on,  97 ;  borers, 
248,  335;  bud-moth,  248,  335;  cigar- 
case-bearer,  251,  335 ;  codlin-moth,  252, 
335;  curculio,  255,  335;  early  treat- 


Index. 


395 


ment  with  fungicides,  47 ;  enemies  and 

diseases,  333-339  ;  fire  blight,  334 ;  fruit 

spot,  333 ;  leaf  blight,  333 ;  blister,  336 ; 

midge,  335 ;  psylla,  331 ;  rust,  242,  335 ; 

scab,  243,  335  ;"slug,  338. 
Pearl  ashes,  11. 

Pearson,  A.  W.,  quoted,  89,  90. 
Peck,  W.  P.,  mentioned,  186. 
Peerless  nozzle,  199. 
Pempelia  Hammondi,  257. 
Pepper,  5,  11,  12,  13. 
Peppier,  T.,  mentioned,  194. 
Perono»pora   effusa,  363;  ScMeideni- 

ana,  319  ;    Violas,  324 ;  vMcola,  300- 

302  ;  see  also  Downy  mildew  of  grape. 
Peroxide  of  silicate,  118. 
Perret,  M.,  quoted,  43,  145. 
Perret's  mixture,  47. 
Persian  insect  powder,  163. 
Petit,  A.,  quoted,  46. 
Petroleum,  5,  152. 
Phenic  acid,  50,  133 ;  and  grape  mildew, 

24. 

Phenol,  133. 
Phlegethontius  Carolina,  370 ;  celeus, 

371. 

Phoma  'uvicola,  297-300. 
Phorbia  Brassicce,  268;  Ceparum,  320. 
Phosphate  of  copper,  44. 
Phoxopteris  comptana,  366. 
Phragmidium mucronatum,  361 ;  rose, 

360 ;  »pecio#um,  360. 
Phyllosticta  Acericola,3l2;  Bataticola, 

368;  Catalpce,  273;    hortorv/m,  290; 

liguttri,  352 ;  vittata,  851. 
Phylloxera,  treatment  of,  135. 
Phytophthora  infestans,  347 ;  Phaseoli, 

264. 

Phytoptus  Pyri,  336. 
Picreena  excelsa,  165. 
Pierce,  N.  B.,  quoted,  239. 
Pieris  Rapce,  268. 
Pigeon  dung,  16. 
Pine  bug,  10. 
Pinolini,  quoted,  21. 
Pistons,  packing,  210. 
Plane  tree,  339. 
Plant-bug,  black-lined,  287;  four-lined, 

287,  290  ;  tarnished,  on  strawberry, 366. 
Plant-lice,  308  ;  early  remedies  for,  5. 
Plasmodiophora  Brassicae,  266. 
Plasmopara  Cubensis,  283,  314. 
Plaster,  carbolized,  134. 


Plowrightia  morbom,  275,  340. 

Plum,  black  knot,  111,  340 ;  bladders, 
342 ;  borers,  248,  343  ;  brown  rot,  339  ; 
bud-moth,  248, 343  ;  canker-worm,  249, 
343  ;  curculio,  332,  343 ;  experiments 
of  Alwood,  69  ;  Cook,  69,  70 ;  Gillette, 
71 ;  Osborn,  70 ;  Weed,  70-73 ;  spray- 
ing for,  68-74  ;  treatment  in  New  York, 
73 ;  Ohio,  73  ;  enemies  and  diseases, 
339-345;  gouger,  344;  knot,  340;  leaf 
blight,  339;  pockets,  342;  powdery 
mildew,  241,  343  ;  rot,  328,  343 ;  scale, 
344 ;  shot-hole  fungus,  339 ;  slug,  275, 
345 ;  wart,  340. 

Plusia  Bra&#icce,  267  ;  cabbage,  267. 

Pneumatic  pumps,  description  of,  192. 

Podechard's  powder,  32 ;  preparation  of, 
163. 

Podosphaira  Oxycanthce,  241,  275,  331. 

Pod  rust,  bean,  261,  263. 

Pole,  use  of,  218. 

Pons,  B.,  quoted,  42. 

Poplar,  345. 

Pot  ashes,  11. 

Potash,  163  ;  soap,  163. 

Potassium,  163  ;  cyanide,  149. 

Potassium  ferrocyanide,  see  Ferrocyanide 
of  potassium  ;  sulphide  and  smut,  318 ; 
and  whale-oil  soap,  180;  early  use  in 
America,  97 ;  in  England,  55 ;  sug- 
gested, 24  ;  use  of,  163. 

Potato,  affected  by  copper  salts,  235 ; 
bacterial  blight,  349 ;  beetle,  290,  351 ; 
appearance  of,  185 ;  early  spread  of,  59, 
60 ;  first  destroyed  by  Paris  green,  60 ; 
blight,  347  ;  bug,  351  ;  downy  mildew, 
347 ;  early  blight,  345 ;  treatment  with 
fungicides,  47 ;  enemies  and  diseases, 
345-352 ;  experiments  on.  in  England, 
55 ;  flea-beetle,  351 ;  late  blight,  347 ; 
rot,  347;  and  Paris  green,  98;  Bor- 
deaux mixture  first  recommended  for, 
29;  treatment  of,  100;  scab,  350; 
sprayer,  Climax,  194;  Monarch,  195; 
sprayers,  221 ;  sweet,  see  Sweet  potato, 
368 ;  water,  10. 

Potatoes,  spraying  with  force  pumps, 
194  ;  gravity  machines,  194. 

Powder,  David's,  33;  guns,  204,  205; 
insect,  163 ;  Podechard's,  32 ;  Ska- 
win  ski's,  170. 

Powders  and  liquids  compared,  205-207  ; 
application  of,  205-207;  first  used 


396 


The  Spraying  of  Plants. 


against  downy  mildew  of  grape,  21 ; 
used  against  grape  mildews,  32. 

Powdery  mildew,  apple,  241 ;  cherry,  275 ; 
cucumber,  283  ;  grape,  303, 304 ;  musk- 
melon,  314;  plum,  241,  343  ;  pumpkin, 
314, 352  ;  squash,  314, 364 ;  watermelon, 
281,  378. 

Power  sprayer,  first  form  advertised, 
193  ;  gas,  196  ;  steam,  195, 196  ;  spray- 
ers, 220,  221. 

Precipitated  copper  carbonate,  187. 

Preparations  for  spraying,  115-180. 

Prevost,  Benedict,  quoted,  22. 

Prillieux,  E.,  quoted,  28,  40. 

Principles  of  nozzle  construction,  198. 

Privet  blight,  352 ;  web-worm,  352. 

Profits  of  spraying,  288. 

Psylla,  pear,  337. 

Psylla  Pyricola,  337. 

Puccinia  Mafoacearum,  811. 

Puceron  lanigere,  50. 

Pump,  air  chambers  of,  210,  211 ;  an  early 
form  recommended  in  America,  184; 
barrel,  method  of  mounting,  212 ;  cyl- 
inders, 210;  first  form  designed  for 
spraying,  191 ;  handles,  210 ;  horizon- 
tal-acting, 214,  216 ;  new  type,  192 ;  pis- 
tons, 210 ;  valves,  208. 

Pumps  and  syringes,  history  of,  181-197 ; 
barrel,  209-220;  brass  for,  207,  208; 
bucket,  208,  209 ;  clock,  217 ;  durabil- 
ity of,  217;  knapsack,  uses  of,  208; 
semi-rotary,  215-217 ;  types  of,  213-220. 

Pumpkin,  powdery  mildew,  314,  352. 

Pupa  of  insects,  228. 

Pyrethro-kerosene  emulsion,  156. 

Pyrethrum,  52  ;  and  alum,  116 ;  intro- 
duction of,  78  ;  preparation,  163,  164 ; 
uses  of,  164,  165. 

Pyrolignic  acid,  52. 

Quassia,  15,  17,  18,  165 ;  and  soap,  165, 
166. 

Quicklime,  11,  12  ;  chemistry  of,  156. 

Quince,  black  rot,  353 ;  blight,  334,  353  ; 
enemies  and  diseases,  353-355;  fruit 
spot,  353  ;  insects  affecting,  355,  see 
also  Apple  ;  leaf  blight,  334,  353 ;  spot, 
853 ;  ripe  rot,  240,  354 ;  rust,  111,  354. 

Eadclyffe,  W.  F.,  quoted,  17. 

Radish,  insects  affecting,  355;  see  Cab- 


Railroad-worm,  of  apple,  257. 

Rain,  action  of  on  fungicides,  47. 

Raspberry  anthracnose,  101,  355;  cane 
borer,  357  ;  rust,  355 ;  enemies  and  dis- 
eases, 355  358 ;  orange  rust,  355 ;  red 
rust,  856 ;  sawfly,  357  ;  slug,  357. 

Rattles,  grape,  304. 

Raupenleim,  250. 

Read's  syringe,  188. 

Red  oxide  of  mercury,  52 ;  rust,  cran- 
berry, 279 ;  raspberry,  356 ;  spider,  10, 
821 ;  treatment  of,  310  ;  spotted  mite, 
on  orange,  321. 

Resin  and  soda  wash,  172  ;  compounds 
and  arsenicals,  136 ;  first  use  of,  85-87 ; 
soap,  preparation  of,  166 ;  washes  and 
arsenicals,  169 ;  Bordeaux  mixture, 
136 ;  kerosene  emulsion,  136. 

Resin  washes,  preparation  and  use  of, 
166-169. 

Rhopobata  vacciniana,  280. 

Rig  for  spraying,  218-220. 

Riley,  C.  V.,  in  France,  51 ;  mentioned, 
68;  quoted,  59,  60,  61,  64,  85,  203; 
Hubbard  kerosene  emulsion,  155 ;  noz- 
zle, 203,  294;  on  kerosene  emulsion, 
81. 

Ripe  rot,  apple,  240  ;  grape,  305 ;  quince, 
240,  354. 

Robertson,  John,  quoted,  10. 

Rcestelia  aurantiaca,  354;  pirata, 
242. 

Root-maggot,  cabbage,  268 ;  treatment 
of,  135;  rot,  beet,  264;  worm,  south- 
ern corn,  283. 

Rose,  black  spot,  102,  358;  bug,  362; 
chafer,  362 ;  enemies  and  diseases,  358- 
363;  leaf  blight,  358;  hopper,  363; 
spot,  358 ;  mildew,  359 ;  and  copper 
sulphate,  17  ;  Phragmidium,  360  ;  rust, 
102,  361. 

Rose,  used  for  spraying,  198. 

Rosette,  peach.  332. 

Rot,  bitter,  grape,  305;  black,  quince, 
358 ;  sweet  potato,  368  ;  brown,  grape, 
300-302  ;  peach,  328 ;  plum,  339  ;  cran- 
berry, 279 ;  fruit,  peach,  328 :  gray, 
grape,  300-302  ;  plum,  328,  343  ;  potato, 
347  ;  grape,  305 ;  tomato,  370. 

Rubber  in  pumps,  208. 

Rue,  4,  5,  8. 

Rumsey  &  Co.,  mentioned,  189,  190,  191, 
199. 


Index. 


397 


Rust,  apple,  242 ;  bean,  263  ;  beet,  265 ; 

cane,  of  raspberry.  355 ;  carnation,  272 ; 

celery,   274;  currant,   285;  hollyhock, 

311 ;  mite,  orange,  322 ;  onion,  319 ; 

pansy,  324 ;  pea,  326 ;  pear,  242,  335 ; 

quince,  111,  354 ;  red,  cranberry,  279  ; 

raspberry,  356 ;  rose,  361 ;  strawberry, 

364 ;  verbena,  281,  372 ;  violet,  372. 
Busts,  of  grains,  319. 

Sage,  5. 

Salicylic  acid,  52. 

Salt,  9,  11 ;  lime,  and  copper  sulphate 
wash,  162 ;  sulphur  wash,  157 ;  use  of, 
169. 

Sand,  6. 

San  Jose  scale,  323. 

Saperda  Candida,  248 ;  cretata,  248. 

Saprophitic  fungi,  229. 

Saunders,  W.,  mentioned,  88;  quoted, 
249,  253. 

Sawfly,  currant,  286;  gooseberry,  286; 
grape,  305 ;  raspberry,  357 ;  straw- 
berry, 366  ;  sweet  potato,  368. 

Scab,  apple,  243-247 ;  beet,  265  ;  grape, 
294 ;  orange,  320 ;  pear,  243,  335  ;  po- 
tato, 350. 

Scald,  cranberry,  279. 

Scale,  Glover's,  322 ;  insects,  treatments 
of,  7,  84,  150 ;  plum,  344 ;  San  Jose,  323. 

Scheele's  green,  120. 

ScMsocerus  ebenus,  368 ;  privatus.  368. 

Sckizoneura  lanigera,  259. 

Schnorff,  23,  37. 

Schweinfurth's  green,  121. 

Scribner,  F.  Lara  son,  quoted,  91,  93,  242. 

Sea,  sand,  8 ;  shells,  8 ;  water,  7 ;  weed,  8. 

Section  of  Veg.  Path,  foundation  of,  92. 

Seeds,  treatment  of,  135. 

Selandria  Cerasi,  275 ;  Rubi,  357 ; 
Vitis,  305. 

Semi-rotary  pumps,  215-217. 

Septoria  cerasina,  839 ;  Chrysan- 
themi,  275;  Dianthi,  273;  Petrose- 
Uni,  274 ;  Jiibis,  285. 

Sesia  tipuliformis,  286. 

Shade  trees,  spraying,  195,  196,  363. 

Sheep,  injured  by  sprayed  grape  foliage, 
234. 

Shelling,  grape,  304. 

Shot-hole  fungus,  plum,  339. 

Shrubs,  363. 

Siebe's  syringe,  183. 


Sirocco  Dust  Sprayer,  205. 
Skawinski,  quoted,  45. 
Skawinski's  iron  sulphate  and  sulphuric 
acid,  169,  170 ;  powder,  44,  170 ;  sul- 
phur, 44. 

Slingerland,  M.  V.,  quoted,  248, 252,  288. 
Slug,  311 ;  cherry,  275 ;  grape,  305 ;  pear, 
338 ;  plum,  275,  345 ;  raspberry,  357 ; 
strawberry,  366. 
Slugs,  8,  11. 
Smith,    G.  M.,    mentioned,    68;    John, 

quoted,  75 ;  J.  B.,  quoted,  250. 
Smoke,  tobacco,  177. 
Smut,  barley,  261 ;  corn,  276  ;  hot  water 
and,    315-319;    loose    oats,     315-319; 
wheat,  315-319,  373 ;  onion,  319 ;  po- 
tassium sulphide  for,  318  ;  stinking,  of 
•wheat,  315-319,  373;  wheat,  and  cop- 
per sulphate,  318. 
Smuts,  treatment  of,  106. 
Snail,  811. 
Snuff,  177 ;  and  sulphur,  176 ;  uses  of, 

170. 

Soap,  5,  6,  7,  11 ;  and  arsenites,  prepara- 
tion of,  170  ;  carbolic  acid,  134  ;  kero- 
sene, emulsions  of,  154;  lime  wash, 
171 ;  quassia,  165, 166 ;  soda  wash,  171 ; 
tobacco,  171;  black,  50,  52;  fish-oil, 
146, 171 ;  potash,  163 ;  resin,  first  use 
of,  85;  preparation  of,  166;  standard 
remedy,  18 ;  use  of,  170 ;  whale-oil, 
uses  of,  179. 

Soda  and  aloes,  172 ;  resin  wash,  172 ; 
soap  wash,  171 ;  whale-oil  soap  wash, 
172. 

Soda  wash,  172. 

Sodium  arsenate,  120  ;  experiments  with, 
77 ;  borate  and  grape  mildew,  23 ;  car- 
bonate, 52 ;  and  copper  sulphate,  36, 
44;  chloride,  169;  hyposulphite  and 
copper  sulphate,  141 ;  first  use  of,  88 ; 
use  of,  172 ;  sulphide  wash,  prepara- 
tion of,  173. 

Soft  soap  and  kerosene,  154. 
Soil,  affected  by  copper  salts,  236;  in- 
secticides and  fungicides,  235-237. 
Soot,  5,  7,  13. 

Sostegni,  L.,  mentioned,  128. 
Soufres  des  Tapets,  21. 
Sour  milk  and  kerosene,  153. 
Southern  corn  root-worm,  283. 
Span-worm,  elm,  291. 
Sphaceloma  Ampelinum,  294-296. 


398 


The  Spraying  of  Plants. 


Sphcerella  Fragarice,  364. 

Sphceria,  275,  840  ;  morbosa,  275,  340. 

Sphceropsis  malorum,  241,  353. 

Sphcerotheca  Castagnei,  365  ;  Jfors- 
uvce,  292  ;  pannosa,  359. 

Spider,  orange,  321 ;  red,  treatment  of, 
310. 

Spinach,  anthracnose,  863 ;  mildew, 
363. 

Spores,  use  of,  229. 

Spot,  black,  of  rose,  358  ;  carnation,  273 ; 
leaf,  of  rose,  358. 

Spotted  cucumber-beetle,  283. 

Spray,  character  of,  218,  222-224;  ma- 
chinery, care  of,  224. 

Sprayed  fruit,  keeping  qualities  of,  238. 

Sprayer,  dust,  Sirocco,  205 ;  power,  first 
form  advertised,  193. 

Sprayers,  potato,  221  ;  power,  220,  221. 

Spraying,  definition,  3 ;  in  America.  59- 
114 ;  in  1886,  92-99 ;  in  1887,  99-102 ; 
in  1888,  102,  103 ;  in  1889,  103-106 ;  in 
1890,  106-108  ;  in  1891,  108-110  ;  since 
1892, 110-112;  in  Australia,  57;  Canada, 
112;  England,  54;  Europe,  53  ;  France 
in  1885,  29  ;  in  1886,  80 ;  in  1887,  34 ; 
in  1888, 88 ;  in  1889,  41 ;  Germany,  54 ; 
Italy,  53 ;  Nova  Scotia,  113 ;  laws,  58, 
376-^381 ;  machine,  gas  engine,  196 ; 
steam  power,  196 ;  machinery,  207-224 ; 
early  forms,  185 ;  method  of,  226 ;  old 
orchards,  218;  profits  of,  238;  tank, 
218,  219  ;  value  of,  237,  238. 

Squash,  insects  affecting,  814,  364 ;  pow- 
dery mildew,  314,  364. 

Standard  Bordeaux  mixture,  108,  130. 

Starr,  R.  W.,  quoted,  113. 

Steam  spraying  machine,  195,  196. 

Steely -bug,  grape,  306. 

Stinking  smut,  wheat,  315-319,  373. 

Stock  in  sprayed  orchards,  233,  234 ;  so- 
lutions suggested,  34. 

Strawberry,  leaf  blight,  364 ;  roller,  366  ; 
mildew,  365 ;  rust,  364 ;  sawfly,  366 ; 
slug,  366;  sunburn,  364;  tarnished 
plant-bug,  366. 

Striped  cucumber-beetle,  284. 

Strychnine,  75. 

Sugar,  and  copper  compounds,  178. 

Sulphate,  of  ammonia,  44 ;  of  copper,  142  ; 
see  also  Copper  sulphate ;  and  wheat 
smut,  318  ;  of  iron,  see  Iron  sulphate. 

Sulphated  sulphur,  44,  174 ;  verdet,  44. 


Sulfatine,  33 ;  analysis  of,  118 ;  in  Aus- 
tralia, 57 ;  powder,  preparation  of, 
174. 

Sulphide  of  lime,  16;  preparation  of, 
158  ;  potassium,  51,  180  ;  and  kerosene 
emulsion,  180 ;  smuts,  318 ;  in  England, 
55 ;  soda  wash,  preparation  of,  178. 

Sulphocyanide  of  copper,  44. 

Sulphosaccharate  of  copper,  42,  173. 

Sulphosteatite,  44 ;  early  use  of,  33 ;  in- 
troduction of,  174 ;  tested,  38, 41 ;  value 
of,  49. 

Sulphur,  10,  11,  12,  13,  175 ;  and  copper 
hydrate,  44  ;  cuprophosphate,  44 ;  lime 
mixture,  147 ;  powder,  176 ;  lye,  159  ; 
snuff,  176;  Sulphosteatite,  49;  whale- 
oil  soap,  176 ;  in  America,  88  ;  salt,  and 
lime  wash,  157  ;  sulphated,  44, 174 ;  use 
of,  in  greenhouse,  807. 

Sulphuret  of  potassium,  163. 

Sulphuric  acid,  45 ;  and  copper  sulphate, 
143;  iron  sulphate,  169,  179;  as  a 
fungicide,  22. 

Sunburn,  strawberry,  364. 

Sun-scald,  celery,  274. 

Sweet  potato,  black  rot,  368;  golden- 
bugs,  369  ;  leaf-mold,  368 ;  spot,  368 ; 
sawfly,  368;  tortoise-beetles,  369; 
white  mold,  368. 

Swingle,  W.  T.,  mentioned,  106. 

Switzer,  S.,  quoted,  15. 

Sycamore  leaf  blight,  369. 

Synchytrium  Vaccinii,  279. 

Syringe,  7. 

Syringes,  early  forms  of,  183 ;  uses  of, 
183,  208. 

Syringing,  definition,  3. 

Tank  for  spraying,  218,  220. 

Tanks,  agitators  for,  211-213. 

Tanner's  bark,  8. 

Tansy,  5. 

Taphrina,  47,  342. 

Tar,  136 ;  water,  8,  11. 

Tarnished  plant-bug,  strawberry,  866. 

Tasmania,  spraying  in,  57,  58. 

Tavelure,  47. 

Tent  caterpillars  and  arsenate  of  lead. 

77 ;  on  apple,  258 ;  for  gas  treatments, 

150. 
Telranychus  Mmaculaius,  309 ;  6-ma 

culatus,  321 ;  telarius,  310. 
Thacher,  J.,  quoted,  7,  8,  9. 


Index. 


399 


Thick-thighed  walking-stick,  64. 

Thrip,  grape,  806. 

Thrips,  10. 

Tilletiafateus,  315,  319,  373. 

Tmetocera  ocellana,  248. 

Tobacco,  8,  10,  11,  13, 18,  170 ;  and  soap, 
171 ;  for  plant-lice,  5 ;  liquor,  analysis 
of,  118 ;  stems,  use  of,  308 ;  uses  of, 
176-178 ;  worm,  370. 

Tomato,  blight,  370 ;  rot,  370 ;  first  treat- 
ments of,  28,  29;  treatment  of,  100; 
worm,  37. 

Tortoise  beetles,  sweet  potato,  369. 

Tozzetti,  A.  T.,  quoted,  145. 

Train-oil,  7. 

Trypeta  pomonella,  257. 

Tschirch,  A.,  quoted,  235. 

Tuck,  quoted,  16. 

Turnip  fly,  13 ;  maggot,  268,  372. 

Turpentine,  5,  8,  11. 

Tussock-moths,  313. 

Twig  blight,  peach,  328 ;  pear,  334. 

Typhlocyba  rosce,  363. 

Uncinula  tpiralin,  303,  304. 

Urine,  4,  7, 16. 

Urocystis  Cepulw,  319. 

Uromyces  Beta*,  265 ;  Ciryophyttinus, 

272 ;  Phawoli,  268. 
Unlikigo  Maydis,  276 ;  Tritici,  315-319, 

373. 

Valves,  208. 

Vanessa  antiopa,  373. 

Veratrwm  album,  148. 

Verbena  mildew,  281,  872 ;  mite,  309 ; 

rust,  281,  372. 

Verdet,  44, 137 ;  sulphated,  44. 
Verdigris,  137. 
Vermorel,  nozzle,  204 ;  with  lance,  204 ; 

V.,  mentioned,  203,  204. 
Vigouroux  knapsack   pump,  187,  188 ; 

nozzle,  201. 
Vinegar  for  canker,  4 ;  cleaning  grapes, 

105 ;   insects,  11 ;   in  kerosene  emul- 
sions, 153. 

Vine- worm,  cranberry,  280. 
Vineyards,    American,    and    fungi,    89 ; 

early  treatment  of,  89,  90  ;  commercial 

treatment  in  America,  105. 
Violet,  disease,  372 ;  mildew,  324,  372 ; 

rust,  372 ;  spot,  372. 
Vitriol,  blue,  142  ;  green,  15J, 


Volatile  alkali,  116. 
Volutella,  sp.,  271. 

Walnut  leaves,  7,  11, 13. 

Warner's  syringe,  183. 

Wash  for  insects,  6,  178 ;  resin,  first 
made,  85. 

Washes,  clay,  178;  resin,  preparation 
and  use  of,  166-169. 

Water,  11, 178;  cold,  179;  hot,  11,  179; 
for  smut,  315-318 ;  sea,  7. 

Watering  can,  description,  182, 183. 

Watermelon  anthracnose,  261, 373 ;  pow- 
dery mildew,  281,  373. 

Webster,  F.  M.,  quoted,  251. 

Web- worm,  fall,  apple,  256;  parsnip, 
325;  privet,  352. 

Weed,  C.  M.,  and  plum  curculio,  70 ; 
quoted,  105,  366. 

Weed,  H.  E.,  mentioned,  197. 

Weevil,  bean,  263 ;  pea,  326. 

Weigelia,  insects  affecting,  286,  373. 

Weights  and  measures,  382,  383. 

Wellhouse,  nozzle,  200, 210 ;  Walter,  men- 
tioned, 200. 

Whale-oil,  7;  soap  and  lye,  159;  potas- 
sium sulphide,  180 ;  soda  wash,  172 ; 
sulphur,  176 ;  first  use  of,  14 ;  uses  of, 
179. 

Wheat,  loose  smut,  315,  319,  373 ;  rust, 
319;  smut  and  copper  sulphate,  318; 
stinking  smut,  315-319,  373;  arsenic, 
117. 

White  arsenic,  117,  see  also  Arsenic; 
hellebore,  148,  see  also  Hellebore; 
mold,  sweet  potato,  368;  oxide  of 
arsenic,  117 ;  scaly  coccus,  10. 

Whitman's  fountain  pump,  184. 

Whitney,  A.  E.,  quoted,  67. 

Willard,  S.  D.,  quoted,  73. 

Willow,  antiopa  butterfly,  373;  worm, 
278,  292,  373. 

Woodchucks,  treatment  of,  135. 

Woodward,  J.  S.,  quoted,  63,  64. 

Woolly  aphis,  10;  destruction  of,  50; 
on  apple,  259. 

Worms,  11. 

Wormwood,  5,  7,  8. 

Yellow-fined  currant-bug,  287. 
Yellow  prussiate  of  potash,  146. 
Yellows,  peach,  332. 
Young,  Lawrence,  quoted,  16. 


THE  GARDEN-CRAFT  SERIES. 

By  L.  H.  BAILEY. 

T  TNDER  this  title,  MACMILLAN  &  Co.  are  issuing  a  series  of 
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PLANT-BREEDING. 

BY 

L.    H.    BAILEY, 

PROFESSOR  OF  HORTICULTURE  IN  THE  CORNELL  UNIVERSITY;  EDITOR  OF 
"THE  RURAL  SCIENCE  SERIES,"  ETC. 

izmo.     293  pages.     Cloth.     Price  $1.00. 

CONTENTS. 

LECTURE     I.  The  Fact  and  Philosophy  of  Variation. 

"          II.  The  Philosophy  of  the  Crossing  of  Plants. 

"        III.  Specific  Means  by  which  Garden  Varieties  originate. 

IV.  Borrowed  Opinions,  of  B.  Verlot,  E.  A.  Carriere,  and  W.  O. 

Focke,  on  Plant-Breeding. 

"          V.  Detailed  Directions  for  the  Crossing  of  Plants. 
GLOSSARY. 


THE   MACMILLAN   COMPANY, 

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The  Horticulturist's  Rule-Book. 

A   COMPENDIUM    OF   USEFUL   INFORMATION  FOR   FRUIT-GROWERS 
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By  L.  H,  BAILEY* 

Professor  of  Horticulture  in  the  Cornell  University. 
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comprising  full  estimates  and  tables  of  heating  glass-houses,  list  of  plants  for 
forcing,  for  cut  flowers,  for  window-gardens,  aquaria,  and  the  like,  with  tem- 
peratures at  which  many  plants  are  grown,  directions  for  making  potting-earth 
and  of  caring  for  plants,  etc. ;  a  chapter  on  "  Literature,"  giving  classified  lists 
of  the  leading  current  writings  on  American  horticulture,  with  publisher's 
addresses  and  prices,  and  a  list  of  periodicals,  and  directories  of  officers  of 
whom  the  bulletins  of  the  various  experiment  stations  may  be  obtained ;  lists 
of  self-fertile  and  self-sterile  fruits;  a  full  account  of  the  method  of  predicting 
frosts  and  of  averting  their  injuries ;  a  discussion  of  the  aims  and  methods  of 
phenology,  or  the  record  of  climate  in  the  blooming  and  leafing  of  trees ;  the 
rules  of  nomenclature  adopted  by  botanists  and  by  various  horticultural  socie- 
ties ;  score-cards  and  scales  of  points  for  judging  various  fruits,  vegetables,  and 
flowers;  a  full  statement  of  the  metric  system,  and  tables  of  foreign  money. 


THE    MACMILLAN   COMPANY, 

66   FIFTH   AVENUE,  NEW  YORK. 


THE  RURAL  SCIENCE  SERIES. 

NOW    READY. 

The  Soil.     By  FRANKLIN  H.  KING,  Professor  of  Agricultural  Physics, 

University  of  Wisconsin.     i6mo.     Cloth,     pp.  303.     75  cents. 
The  Spraying  of  Plants.     By  ERNEST  G.  LODEMAN,  Cornell  University 

pp.  399-     £1-00. 

IN    PREPARATION. 

The  Apple  in  North  America.     By  L.  H.  BAILEY,  Editor  of  the  Series 

The  Fertility  of  the  Land.     By  I.  P.  ROBERTS,  Cornell  University. 

Milk  and  its  Products.     By  H.  H.  WING,  Cornell  University. 

Bush  Fruits.     By  FRED  W.  CARD,  University  of  Nebraska. 

The  Grass.     By  W.  H.  BREWER,  Yale  College. 

The  Feeding  of  Animals.     By  W.  H.  JORDAN,  Experiment  Station  of 

Maine. 
Leguminous  Plants  and  Nitrogen-Gathering.      By  E.  W.  HILGARD, 

University  of  California. 

Irrigation.     By  F.  H.  KING,  author  of  "The  Soil." 
Seeds  and  Seed-Growing.     By  GILBERT   H.  HICKS,  Curator  of  Seeds, 

Division  of  Botany,  Department  of  Agriculture. 
Physiology  of  Plants.     By  J.  C.  ARTHUR,  Purdue  University. 
Pathology  of  Plants.     By  B.  T.  GALLOWAY,  Chief  of  the  Division  of 

Vegetable  Pathology,  Department  of  Agriculture,  assisted  by  ERWIN 

F.  SMITH  and  ALBERT  F.  WOODS. 


I  TNDER  the  editorship  of  Professor  L.  H.  BAILEY  of  Cornell  University, 
*-'  MACMILLAN  &  Co.  purpose  issuing  a  series  of  books  upon  agricultu- 
ral subjects  to  be  known  as  the  Rural  Science  Series.  These  volumes 
are  designed  to  treat  rural  subjects  fundamentally,  setting  forth  in  readable 
form  the  latest  and  best  science  and  opinion  as  applied  to  agriculture  in 
its  broadest  sense.  Whilst  it  is  expected  that  the  books  shall  describe  the 
current  practices  of  rural  occupations,  it  is  nevertheless  their  chief  mission 
to  expound  the  principles  which  underlie  these  practices,  and  thereby  to 
lead,  by  true  educational  methods,  to  the  betterment  of  every  rural  pur- 
suit. These  monographs  are  to  be  written  by  men  of  recognized  attain- 
ments, in  various  parts  of  the  country;  and  it  is  expected  that  the  seriej 
will  be  continued  from  year  to  year  until  it  eventually  covers  the  whole 
field  of  agriculture. 

THE    MACMILLAN   COMPANY 

64-66  FIFTH  AVENUE,   NEW  YORK 


FOURTEEN  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

ENTOMOLOGY  LIBRARY 

This  book  is  due  on  the  last  date  stamped  below,  or 

on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


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